Calculus: tangent to the curve

Question

find an equation for the line that is tangent to the curve y=2x^3-8x at the point (-2,0) 

Answer 1

y = 2x³ - 8x

 

y' = 6x² - 8

 

m = y'(-2) = 6(-2)² - 8 = 16

 

y = mx + b = 16x + b

 

0 = 16(-2) + b

 

b = 32

 

y = 16x + 32