Conjugate
Radical expressions that are identical except for the plus/minus sign in the middle. Expressions like (
a +
b) and (
a –
b) are conjugates. They're sort of the evil twins of the math world.
Distributive Property
Multiplication of numbers that distributes over addition and subtraction:
a(
b ±
c) =
ab ±
ac.
Equations
An expression that states the equivalence of two algebraic expressions.
Equivalent Equations
Different equations that have the same solution(s).
Extraneous Solution
A solution to an equation that's formed in the process of simplifying the original equation (for example, taking the square of a radical equation), but is not a valid solution of the original equation. These guys are the worst: they seem like legit solutions when we solve for our variable, but then they run away and scream, "Not!" when we try to plug them back into the equation.
Factoring
Breaking up an algebraic expression into two or more expressions that can be multiplied together to get the original expression.
Like Terms
Two terms with the exact same radical. If the stuff inside the radical (the radicand) matches, we can combine those terms just like we do with like variables.
Principal Square Root
The positive square root of a number. Way more useful in real-life situations than their negative brethren.
Pythagorean Theorem
The fact that the sum of the squares of a right triangle's legs is equal to the square of its hypotenuse. Or as most people would prefer to remember it,
a2 +
b2 =
c2.
Quadratic Equation
An equation obtained by setting a quadratic polynomial equal to zero. We can solve these beasts by factoring, completing the square, or busting out the quadratic formula.
Quadratic Formula
A formula for finding the roots of a quadratic equation:
Quadratic Polynomial
A polynomial of degree two.
Radical Equation
An equation with a variable that's contained inside a radical symbol. Usually seen toting around a skateboard and wearing a backwards ball cap.
Radical Sign
The symbol of a square root. It sort of looks like a really elaborate check mark: √.
Radicand
The value inside the radical symbol. For example, 5 is the radicand of
.
Rationalizing The Denominator
Rewriting the fraction to get rid of the radical in the denominator.
Square
A number raised to the power of two.
Square Root
The inverse operation of squaring a number.
Solution
Values that we can plug into a variable in an equation that make the equation true. Got a problem? Find the solution.
Variable
A value that changes. Variables are commonly represented by the letters
x,
y, or
z.