Unit 4 Math Vocab

Complex Number

A number written in the form of 𝑎+𝑏𝑖, where 𝑎 and 𝑏 are real numbers.

Quadratic Equation in One Variable

An equation that can be written in the standard form 𝑎𝑥2 +𝑏𝑥+𝑐 =0, where 𝑎, 𝑏, and 𝑐 are real numbers and 𝑎 ≠0

Imaginary Unit 𝑖

An imaginary number, the square root of −1. √−1=𝑖

Quadratic Inequality

An inequality of the form 𝑦<𝑎𝑥2 +𝑏𝑥+𝑐, 𝑦>𝑎𝑥2 +𝑏𝑥+𝑐, 𝑦≤𝑎𝑥2 +𝑏𝑥+𝑐, or 𝑦≥𝑎𝑥2 +𝑏𝑥+𝑐 where 𝑎, 𝑏, and 𝑐 are real numbers and 𝑎 ≠0

Zero of a Function

An 𝑥-value of a function 𝑓 for which𝑓(𝑥)=0.

Discriminant

The expression 𝑏2 −4𝑎𝑐 in the Quadratic Formula

Root of an Equation

The solution of an equation.

Quadratic Formula

The solutions of the quadratic equation 𝑎𝑥2 +𝑏𝑥+𝑐 =0 are 𝑥 =−𝑏±√𝑏2−4𝑎𝑐2𝑎 , where 𝑎, 𝑏, and 𝑐 are real numbers and 𝑎 ≠0

Completing the Square

To add a term 𝑐 to an expression of the form 𝑥2 +𝑏𝑥 such that 𝑥2 +𝑏𝑥+𝑐 is the perfect square trinomial.