f(x) = x² + 4x - 6
f'(x) = (x²)' + 4 * (x)' - 6' = 2x + 4 * 1 - 0 = 2x + 4
f'(- 2) = 2 * (- 2) + 4 = - 4 + 4 = 0
f'(- 2) = 0
f(x) = x² + 4x - 6
f'(x) = (x²)' + 4 * (x)' - 6' = 2x + 4 * 1 - 0 = 2x + 4
f'(- 2) = 2 * (- 2) + 4 = - 4 + 4 = 0
f'(- 2) = 0