Question

Determine the discriminant of x2 = 4.

A. 17
B. 16
C. -15
D. -10

Answer 1

x² = 4

x² - 4 = 0 comparing to ax² + bx + c = 0, a = 1, b = 0, c = -4

Discriminant = b² - 4ac

b² - 4ac = 0² - 4*1*-4 = 0 + 16 = 16

Discriminant = 16.

option B

Answer 2

The discriminant is b²-4ac
We can rewrite x² = 4 to x² + 0x - 4 = 0
So a = 1, b = 0, c = -4
Δ = 0 - 4 * 1 * -4
Δ = 16
The answer is B