Answer:
At the point where x = 2.
Step-by-step explanation:
First find the derivative which gives us the gradient of the tangent at any point on the curve:
y = 5x^2 - 16x
y' = 5*2 x^(2-1) - 16 x(1-1)
y' = 10x - 16.
y' is the gradient at point of coordinate x.
So when the gradient = 4:
4 = 10x - 16
10x = 20
x = 2.
