Algebra Quiz on 5-4, 5-5, 5-6, 5-7, & 5-9

complex conjugates

(a+bi) and (a-bi)

Evaluate the complex Conjugate: -3+7i

-3-7i

Evaluate the complex Conjugate: 9-3i

9+3i

Under which category does 3+2i fall?

Complex Numbers (https://www.ck12.org/trigonometry/complex-numbers/lesson/Defining-Complex-Numbers-ALG-II/) <- scroll down a bit

square root property

If x^2= and a is a nonnegative real number then x=+/-√a

complex number

a+bi, where a and b are real numbers and i is imaginary

pure imaginary number

an imaginary number of the form a+bi where a is 0

discriminant

b²-4ac, when its >0 it has two distinct solutions, when its =0 it has one distinct real solution, when its <0 it has two distinct non-real complex solutions

critical values

exact values of y when x=0

imaginary number

the square root of a negative number, i=√-1

Completing a Square

to complete the square of x^2+bx, add (b/2)^2

quadratic formula

x = [-b ± √(b² - 4ac)]/2a

Evaluate: x^2=-12

x=+/- 2i√3

Evaluate: x^2=-9

x=+/- 3i