Question

Factor f(x) = x2 + 3x − 4.

Answer 1

• (x - 1)(x + 4)

Explanation:

Find zero's of function:

• x² + 3x - 4 = 0
• x = (-3 ± √(3² + 4*4))/2
• x = (-3 ± √25)/2
• x₁ = (-3 + 5)/2 = 1
• x₂ = (-3 - 5)/2 = -4

The factors are:

• x² + 3x - 4 = (x - 1)(x + 4)