Algebra Terms and Definitions
Rules and operations involving powers. Features basic concepts like Base and Power, Laws of Exponents, Exponential Functions (a^x), and applications in growth/decay. Includes special cases like Zero, Negative, and Fractional exponents.
Go to Exponents section →Functions that determine the exponent needed for a base to reach a number. Includes Natural Logarithm (base e), Common Logarithm (base 10), Binary Logarithm (base 2), and their properties. Covers logarithmic functions, equations, identities and transformations.
Go to Logarithms section →Core concepts and operations with roots. Key terms include Square Root (x where x² = n), Cube Root (x where x³ = n), Radical Symbol (√), Perfect Squares/Cubes, and methods of simplification. Covers both real and imaginary roots, radical expressions, and related operations.
Go to Roots section →Roots
Square Root
Definition:
For a number n, its square root is x where x² = n. Denoted as n or n1/2
- Two values: positive and negative
- Real only if n ≥ 0
- (√n)² = n for n ≥ 0
- √(a·b) = √a·√b
- √(a/b) = √a/√b for b > 0
Common square roots:
√4 = ±2
√9 = ±3
√2 ≈ 1.4142 (irrational)
√0 = 0
√(-1) = i (imaginary)
√4 = ±2
√9 = ±3
√2 ≈ 1.4142 (irrational)
√0 = 0
√(-1) = i (imaginary)
Cube Root
Definition:
For a number n, its cube root is x where x³ = n. Denoted as 3n or n1/3
- Only one real value
- Exists for all real numbers
- (∛n)³ = n
- ∛(a·b) = ∛a·∛b
- ∛(a³) = a
Common cube roots:
∛8 = 2
∛27 = 3
∛(-8) = -2
∛1 = 1
∛0 = 0
∛8 = 2
∛27 = 3
∛(-8) = -2
∛1 = 1
∛0 = 0
Radical Symbol
Definition:
√ for square root, nx for nth root where n is the index and x is the radicand
- Index defaults to 2 if omitted
- Index n means nth root
- Radicand is expression under radical
- Can be nested (compound radicals)
Different radical notations:
√x = square root
∛x = cube root
4x = fourth root
nx = nth root
√x = square root
∛x = cube root
4x = fourth root
nx = nth root
Index n must be positive integer ≥ 2
Radicand
Definition:
The expression x under the radical sign in nx. The value we're finding the root of
- Can be any real number for odd roots
- Must be non-negative for even roots
- Can be variable expression
- Can contain other radicals
In these expressions, radicand is:
√16: 16
∛(-27): -27
x+2: x+2
481: 81
√16: 16
∛(-27): -27
x+2: x+2
481: 81
Index (or Degree)
Definition:
The value n in nx indicating which root to take (square, cube, fourth, etc)
- Must be positive integer ≥ 2
- Determines number of roots
- Even index: requires non-negative radicand
- Odd index: allows negative radicand
Common indices:
2 (√): square root
3 (∛): cube root
4: fourth root
n: nth root
2 (√): square root
3 (∛): cube root
4: fourth root
n: nth root
Principal Root
Definition:
For an even root, the non-negative root out of all possible values. For odd roots, the real root
- Always unique
- Used by default for radical symbol
- Non-negative for even roots
- Same sign as radicand for odd roots
Principal roots:
√4 = 2 (not -2)
∛(-8) = -2
416 = 2
x2 = |x|
√4 = 2 (not -2)
∛(-8) = -2
416 = 2
x2 = |x|
Perfect Square
Definition:
A number n = k² where k is an integer. Also called square number
- Always non-negative
- Integer square root
- Square ends in 0,1,4,5,6,9
- Distance between consecutive grows by 2
First perfect squares:
0 = 0²
1 = 1²
4 = 2²
9 = 3²
16 = 4²
25 = 5²
0 = 0²
1 = 1²
4 = 2²
9 = 3²
16 = 4²
25 = 5²
Perfect Cube
Definition:
A number n = k³ where k is an integer. Also called cubic number
- Integer cube root
- Alternates between odd/even
- Growing gaps between consecutive
First perfect cubes:
-8 = (-2)³
-1 = (-1)³
0 = 0³
1 = 1³
8 = 2³
27 = 3³
-8 = (-2)³
-1 = (-1)³
0 = 0³
1 = 1³
8 = 2³
27 = 3³
Nth Root
Definition:
Value x where xn=a, denoted as na or a1/n
- n must be positive integer
- Even n requires a ≥ 0
- Odd n allows any real a
- Principal root is default
Common nth roots:
416=2
532=2
664=2
416=2
532=2
664=2
Radical Expression
Definition:
Mathematical expression containing one or more radicals nx. Can include coefficients, variables, and operations
- Contains at least one radical
- May have coefficients
- Can include variables
- Can be simplified
Radical expressions:
23
x+y
332x
28
23
x+y
332x
28
Simplifying Radicals
Definition:
Converting radical to equivalent form with smallest possible radicand and rational coefficients outside
- Factor radicand
- Remove perfect nth powers
- Combine like radicals
- Rationalize denominators
Steps to simplify:
12=4⋅3=43=23
354=327⋅2=332
12=4⋅3=43=23
354=327⋅2=332
Nested Radicals
Definition:
Expression containing radicals inside other radicals: a+b
- Multiple radical layers
- Can often be simplified
- Harder to manipulate
- Special denesting methods
Nested forms:
5+24
3+1+2
32+5
5+24
3+1+2
32+5
Surd
Definition:
An irrational root of a rational number. A radical that cannot be simplified to a rational number
- Irrational number
- Cannot be further simplified
- Root of rational number
- Contains no imaginary parts
Common surds:
2
3
35
27 (mixed surd)
2
3
35
27 (mixed surd)
Radical Equation
Definition:
Equation containing variable(s) under radical sign: x=a or f(x)=g(x)
- Check for extraneous solutions
- Square both sides carefully
- Domain restrictions apply
- May have multiple steps
Solving x−1=2:
x−1=2
(x−1)2=22
x−1=4
x=5
x−1=2
(x−1)2=22
x−1=4
x=5
Fractional Exponents
Definition:
Root expressions written as powers: xn1=nx and xnm=(nx)m
- Numerator = power
- Denominator = root
- Follow exponent rules
- Equivalent to radicals
x21=x
x31=3x
x32=(3x)2
x31=3x
x32=(3x)2
Rationalizing The Denominator
Definition:
Multiplying numerator and denominator by radical term to eliminate radicals in denominator: ba⋅bb=bab
- Single radical: multiply by itself
- Binomial with radical: multiply by conjugate
- Higher order roots: use appropriate root
21=22
3+21=(3+2)(3−2)3−2
3+21=(3+2)(3−2)3−2
Irrational Root
Definition:
A root that yields an irrational number - cannot be expressed as p/q where p,q are integers, q≠0
- Non-terminating, non-repeating decimal
- Cannot be written as ratio of integers
- Often proved irrational by contradiction
Common irrational roots:
2≈1.4142135...
3≈1.7320508...
32≈1.2599210...
2≈1.4142135...
3≈1.7320508...
32≈1.2599210...
Root Approximation
Definition:
Methods to find approximate values of roots: Newton's method: xn+1=xn−f′(xn)f(xn)
- Newton's method
- Binary search
- Calculator estimation
- Numerical algorithms
2 approximation:
1.4 → 1.414 → 1.4142 → 1.41421
Newton's method for a:
xn+1=21(xn+xna)
1.4 → 1.414 → 1.4142 → 1.41421
Newton's method for a:
xn+1=21(xn+xna)
Conjugate Pair
Definition:
For expression a + √b, its conjugate is a - √b. Product is a² - b. Used to rationalize denominators
- Product removes radicals
- Sum × difference formula
- Preserves value when multiplying num/denom
Conjugate pairs:
a+b and a−b
2+3 and 2−3
(a+b)(a−b)=a2−b
a+b and a−b
2+3 and 2−3
(a+b)(a−b)=a2−b
Logarithmic Connection
Definition:
na=enln(a) and na=b⟺a=bn
- Roots as exponentials
- Natural log connection
- Change of base formula
- Solving using logs
x=e2ln(x)
3x=e3ln(x)
ln(x)=21ln(x)
3x=e3ln(x)
ln(x)=21ln(x)
Higher-Order Roots
Definition:
nth root where n > 3: na is value x where x^n = a
- n can be any positive integer
- Even n requires a ≥ 0
- Odd n allows any real a
- Multiple complex roots
Fourth root: 416=2
Fifth root: 532=2
General: nan=∣a∣ for even n
Fifth root: 532=2
General: nan=∣a∣ for even n
Imaginary Root
Definition:
For negative real number -a, its square root is i√a where i = √(-1). Higher even roots also yield imaginary results
- Occur when taking even roots of negatives
- Involve imaginary unit i
- Come in conjugate pairs
- Real when n is odd
−4=2i
−9=3i
4−16=2(1+i)
Powers of i:
i2=−1
i3=−i
i4=1
−9=3i
4−16=2(1+i)
Powers of i:
i2=−1
i3=−i
i4=1
Logarithms
Logarithm
Definition:
For positive numbers b=1 and x>0, logb(x)=y means by=x. Written as: logb(x)=y⟺by=x
- Base b>0 and b=1
- One-to-one function
- Inverse of exponential
log2(8)=3 because 23=8
log3(27)=3 because 33=27
log10(100)=2 because 102=100
log3(27)=3 because 33=27
log10(100)=2 because 102=100
Base
Definition:
The positive number b ≠ 1 in logarithmic expression logb(x) or exponential expression bx
- Must be positive
- Cannot equal 1
- Common bases: 10, e, 2
- Determines growth rate
Common bases:
log10(x) (common log)
loge(x) (natural log, ln)
log2(x) (binary log)
log10(x) (common log)
loge(x) (natural log, ln)
log2(x) (binary log)
Exponent
Definition:
The power y in exponential form by or the value of logarithm logb(x) where by=x
- Can be any real number
- Results in logarithm value
- Determines output level
- Key in exponential growth
In 23=8:
Exponent is 3
log2(8)=3
In 10x=1000:
x=log10(1000)=3
Exponent is 3
log2(8)=3
In 10x=1000:
x=log10(1000)=3
Natural Logarithm
Definition:
Logarithm with base e(≈2.71828...), written as ln(x) or loge(x). Inverse of exponential function ex
- Used in continuous growth
- Base e is irrational
- Standard notation ln(x)
ln(e)=1
ln(e2)=2
ln(1)=0
ln(ex)=x
Common Logarithm
Definition:
Logarithm with base 10, written as log(x) or log10(x). Used for decimal representations
- Counts decimal digits
- Often written without base
- Standard notation log(x)
log(100)=2
log(1000)=3
log(10n)=n
log(0.01)=−2
log(1000)=3
log(10n)=n
log(0.01)=−2
Binary Logarithm
Definition:
Logarithm with base 2, written as log2(x). Used in computer science and information theory
- Measures bits needed
- Common in computing
- Standard notation log2(x)
log2(8)=3
log2(16)=4
log2(2n)=n
log2(1024)=10
log2(16)=4
log2(2n)=n
log2(1024)=10
Antilogarithm
Definition:
The inverse logarithm function: if y = logb(x), then antilogb(y)=x=by
- Same as exponential function
- Returns original number
- Preserves base
If log(100)=2
then antilog(2) = 100
If ln(x)=3
then antiln(3) = e³
For log2(8)=3:
antilog₂(3) = 2³ = 8
then antilog(2) = 100
If ln(x)=3
then antiln(3) = e³
For log2(8)=3:
antilog₂(3) = 2³ = 8
Characteristic
Definition:
The integer part n of logarithm where log10(x)=n+d and 0≤d<1
- Indicates magnitude
- Can be negative
- For base 10 equals exponent in scientific notation
For log(234)=2.369:
Characteristic = 2
For log(0.0234)=−1.631:
Characteristic = -2
Characteristic = 2
For log(0.0234)=−1.631:
Characteristic = -2
Mantissa
Definition:
The decimal part d of logarithm where log10(x)=n+d and 0≤d<1
- Always positive
- Independent of decimal point position
- Used in log tables
For log(234)=2.369:
Mantissa = 0.369
For log(0.0234)=−1.631:
Mantissa = 0.369
Mantissa = 0.369
For log(0.0234)=−1.631:
Mantissa = 0.369
Logarithmic Function
Definition:
Function f(x)=logb(x) where b>0,b=1. Inverse of exponential function g(x)=bx
- x>0
- Range: all real numbers
- Strictly increasing if b>1
- Strictly decreasing if 0<b<1
Common forms:
f(x)=ln(x)
f(x)=log10(x)
f(x)=log2(x)
f(x)=ln(x)
f(x)=log10(x)
f(x)=log2(x)
Characteristic curved shape crossing y-axis at (1,0)
Complex Logarithm
Definition:
For complex z=r(cosθ+isinθ), ln(z)=ln(r)+i(θ+2πn) where n is integer
- Has infinite branches
- Principal value when n=0
- Defined except at z=0
ln(−1)=πi+2πni
ln(i)=2πi+2πni
Principal value:
ln(−1)=πi
ln(i)=2πi+2πni
Principal value:
ln(−1)=πi
Discrete Logarithm
Definition:
For integers a,b,m, find x where ax≡b(modm). Written as loga(b)(modm)
- Computationally difficult
- May not exist
- Modular arithmetic based
In mod 7:
23≡1(mod7)
so log2(1)≡3(mod7)
3x≡4(mod7)
x=log3(4)(mod7)
23≡1(mod7)
so log2(1)≡3(mod7)
3x≡4(mod7)
x=log3(4)(mod7)
Logarithmic Scale
Definition:
Scale where values are spaced by powers of base b: positions proportional to logb(x) rather than x
- Compresses large ranges
- Often uses base 10
- Shows percentage changes
Common scales:
pH scale (base 10)
Richter scale (base 10)
Decibels (base 10)
Musical octaves (base 2)
pH scale (base 10)
Richter scale (base 10)
Decibels (base 10)
Musical octaves (base 2)
Scientific notation, sound intensity, earthquake magnitude
Exponential Form
Definition:
Equivalent expression of logb(x)=y as by=x, showing inverse relationship between logarithms and exponents
- Used for solving equations
- Connects exp and log
- Base remains constant
log2(8)=3⟺23=8
ln(x)=4⟺e4=x
log10(1000)=3⟺103=1000
ln(x)=4⟺e4=x
log10(1000)=3⟺103=1000
Logarithmic Identity
Definition:
Fundamental rules for manipulating logarithms with same base b:
Product rule: logb(xy)=logb(x)+logb(y)
Quotient rule: logb(yx)=logb(x)−logb(y)
Power rule: logb(xn)=nlogb(x)
Change of base: logb(x)=loga(b)loga(x)
Quotient rule: logb(yx)=logb(x)−logb(y)
Power rule: logb(xn)=nlogb(x)
Change of base: logb(x)=loga(b)loga(x)
log(30)=log(2⋅15)=log(2)+log(15)
log2(28)=log2(8)−log2(2)=3−1=2
log(x3)=3log(x)
log2(28)=log2(8)−log2(2)=3−1=2
log(x3)=3log(x)
Logarithmic Expression
Definition:
Mathematical expression containing one or more logarithms, may include variables and other operations
- May have variables
- Can be simplified using log rules
- Domain restrictions apply
2ln(x)+3
log(x2+1)
log2(x)+log2(y)
ln(2)ln(x)
log(x2+1)
log2(x)+log2(y)
ln(2)ln(x)
Logarithmic Equation
Definition:
Equation containing logarithmic expressions that must be solved for variable(s)
- Use log properties to simplify
- Convert to exponential form
- Check for extraneous solutions
Solving ln(x)=2:
ln(x)=2
eln(x)=e2
x=e2
Solving log2(x+1)=3:
2log2(x+1)=23
x+1=8
x=7
ln(x)=2
eln(x)=e2
x=e2
Solving log2(x+1)=3:
2log2(x+1)=23
x+1=8
x=7
Logarithmic Inequality
Definition:
Inequality containing logarithmic expressions to be solved: logb(x)<k or logb(f(x))>logb(g(x))
- Consider base when solving
- Domain restrictions crucial
- Direction changes if base < 1
- Convert to exponential form
Solving ln(x)>2:
ln(x)>2
eln(x)>e2
x>e2
log2(x)<3:
x<23
x<8
ln(x)>2
eln(x)>e2
x>e2
log2(x)<3:
x<23
x<8
Asymptote
Definition:
For logarithmic function f(x)=logb(x), vertical asymptote at x=0
- Vertical: x = 0
- Function never crosses
- Defines domain boundary
- Different bases, same asymptote
For y=ln(x):
- Vertical asymptote: x = 0
- As x → 0⁺, y → -∞
- As x → ∞, y grows slowly
- Vertical asymptote: x = 0
- As x → 0⁺, y → -∞
- As x → ∞, y grows slowly
Graph Of A Logarithmic Function
Definition:
Plot of y=logb(x) showing characteristic shape with vertical asymptote and continuous growth
- Domain: x > 0
- Vertical asymptote at x = 0
- Passes through (1,0)
- Continuous and increasing for b > 1
- (b,1) where b is base
- (b1,-1) where b is base
Base-Change Rule
Definition:
loga(x)=logc(a)logc(x) for any base c>0,c=1
- Valid for any positive base
- Commonly used with base e or 10
- Preserves function value
- Useful for calculations
log2(x)=ln(2)ln(x)
log3(x)=log10(3)log10(x)
log3(x)=log10(3)log10(x)
Logarithmic Growth
Definition:
Growth pattern where variable increases by additive constant when input is multiplied by constant: f(cx)=f(x)+k
- Inverse of exponential
- Common in natural processes
- Scale-invariant growth
- pH scale
- Earthquake magnitude
- Sound intensity (decibels)
Logarithmic Transformation
Definition:
Converting data by taking logarithm: y=logb(x) to linearize relationships or normalize distributions
- Compresses large ranges
- Normalizes skewed data
- Linearizes exponential relationships
- Preserves order
- Data visualization
- Economic scales
- Sound measurement
Polynomials
Polynomial
Definition:
An expression consisting of variables, coefficients, and non-negative integer exponents combined using arithmetic operations.
Coefficient
Definition:
A numerical factor that multiplies a variable in a polynomial.
Leading Coefficient
Definition:
The coefficient of the term with the highest degree in a polynomial.
Free Coefficient
Definition:
The constant term in a polynomial with no variable attached.
Polynomial Degree
Definition:
The highest exponent of the variable in a polynomial.
Monic Polynomial
Definition:
A polynomial whose leading coefficient is 1.
Zero Polynomial
Definition:
A polynomial where all coefficients are zero.
Zero Function
Definition:
A function that always evaluates to zero for any input.
Undefined Degree
Definition:
The degree of the zero polynomial, which is not defined.
Minus Infinity Degree
Definition:
An informal term sometimes used to describe the degree of the zero polynomial.
Polynomial Equation
Definition:
An equation that sets a polynomial equal to another expression, typically zero.
Polynomial Addition
Definition:
The sum of two or more polynomials by adding corresponding terms.
Polynomial Subtraction
Definition:
The difference of two polynomials by subtracting corresponding terms.
Polynomial Multiplication
Definition:
The product of two polynomials by distributing terms.
Polynomial Division
Definition:
The process of dividing one polynomial by another, yielding a quotient and remainder.
Dividend
Definition:
The polynomial being divided in a division operation.
Divisor
Definition:
The polynomial by which another polynomial is divided.
Quotient
Definition:
The result of polynomial division before considering the remainder.
Remainder
Definition:
The leftover polynomial after division that cannot be further divided by the divisor.
Rational Function
Definition:
A function expressed as the ratio of two polynomials.
Remainder Theorem
Definition:
A theorem stating that the remainder when a polynomial P(x) is divided by (x - a) is P(a).
Root Of A Polynomial
Definition:
A value of the variable that makes the polynomial equal to zero.
Sum Of Coefficients Rule
Definition:
The sum of all coefficients of a polynomial is found by evaluating it at x = 1.
Factoring
Definition:
Expressing a polynomial as a product of simpler polynomials.
Quadratic Formula
Definition:
A formula used to find the roots of a quadratic polynomial.
Complex Roots
Definition:
Non-real solutions of a polynomial equation, often involving imaginary numbers.
Multiplicity Of A Root
Definition:
The number of times a particular root appears in the factorization of a polynomial.
Fundamental Theorem Of Algebra
Definition:
A theorem stating that every non-constant polynomial has at least one complex root.
Existence Theorem
Definition:
A principle ensuring the existence of at least one solution for a given polynomial equation.
Factorization
Definition:
The decomposition of a polynomial into a product of lower-degree polynomials.
Polynomial Derivative
Definition:
The derivative of a polynomial function, obtained by differentiating each term.
Increased Root
Definition:
A root of a polynomial whose multiplicity is greater than one.
Linear Factorization
Definition:
Expressing a polynomial as a product of linear factors corresponding to its roots.
Educated Guess Theorem
Definition:
A strategy for guessing rational roots of polynomials using integer coefficients.
Integer Coefficients
Definition:
A polynomial where all coefficients are whole numbers.
Rational Root Theorem
Definition:
A theorem that provides a possible set of rational roots for a polynomial with integer coefficients.
Factorization Theorem
Definition:
A theorem stating that polynomials can be factored uniquely over specific number systems.
Polynomial Long Division
Definition:
A division algorithm for polynomials similar to numerical long division.
Multiple Root
Definition:
A root of a polynomial that appears more than once.
Finite Field
Definition:
A mathematical field containing a finite number of elements.
Modular Arithmetic
Definition:
A system of arithmetic where numbers wrap around after reaching a fixed modulus.
Polynomial Factorization In Finite Fields
Definition:
The process of breaking a polynomial into irreducible factors within a finite field.
Quadratic Residue
Definition:
A number that is a square modulo a given prime number.
Polynomial Roots In Finite Fields
Definition:
The solutions to a polynomial equation within a finite field.
Fundamental Theorem Of Algebra (Finite Fields)
Definition:
A theorem stating that a polynomial of degree n over a finite field has at most n roots in that field.
Direct Substitution Method
Definition:
A technique for solving polynomials by directly substituting values.
Quadratic Formula In Finite Fields
Definition:
A modified version of the quadratic formula adapted for finite fields.
Multiple Root In Finite Fields
Definition:
A root of a polynomial in a finite field that has higher multiplicity.
Vieta's Formulas
Definition:
A set of equations relating the coefficients of a polynomial to sums and products of its roots.
Sum Of Roots
Definition:
The sum of the roots of a polynomial, given by Vieta’s formulas.
Product Of Roots
Definition:
The product of the roots of a polynomial, also given by Vieta’s formulas.
Coefficient Comparison
Definition:
A method for finding unknown coefficients by equating polynomials.
Root Multiplicity
Definition:
The number of times a particular root appears in the factorization of a polynomial.
Polynomial Expansion
Definition:
The process of expanding a factored polynomial into standard form.
Sigma Notation
Definition:
A compact way to represent summation, often used in polynomial expressions.
Polynomial Factorization Using Roots
Definition:
The process of factoring a polynomial using its known roots.
Quadratic And Higher-Degree Root Relations
Definition:
Relationships between the roots and coefficients of quadratic and higher-degree polynomials.
Exponents
Exponent
Definition:
The power to which a base is raised in a mathematical expression.
Base
Definition:
The number that is raised to the power of the exponent.
Power
Definition:
The result of raising a base to an exponent.
Exponential Function
Definition:
A function of the form f(x) = a^x, where a > 0 and a ≠ 1.
Exponential Growth
Definition:
A process that increases proportionally to its current value, modeled by an exponential function.
Exponential Decay
Definition:
A process that decreases proportionally to its current value, modeled by an exponential function.
Scientific Notation
Definition:
A method of writing numbers using powers of 10.
Negative Exponent
Definition:
Indicates the reciprocal of the base raised to the corresponding positive exponent (a^(-n) = 1/a^n).
Zero Exponent
Definition:
Any nonzero base raised to the power of zero equals 1 (a^0 = 1).
Fractional Exponent
Definition:
Represents a root, where a^(1/n) = √[n]{a}.
Integer Exponent
Definition:
An exponent that is a whole number.
Exponential Equation
Definition:
An equation in which variables appear in exponents.
Exponential Inequality
Definition:
An inequality involving exponential expressions.
Exponential Series
Definition:
A mathematical expansion of e^x as a sum of terms.
Exponentiation
Definition:
The mathematical operation of raising one quantity to the power of another.
Laws Of Exponents
Definition:
Rules governing exponentiation, such as the product, quotient, and power rules.
Exponential Curve
Definition:
The graph of an exponential function, showing rapid increase or decrease.
Natural Exponential Function
Definition:
The exponential function with base e, f(x) = e^x.
Compound Interest Formula
Definition:
A financial formula based on exponential growth, A = P(1 + r/n)^(nt).
Exponential Notation
Definition:
A shorthand way to write repeated multiplication of the same factor.