Find the slope of the tangent to the curve

Find the slope of the tangent to the curve

y = 3 + 4x^2 - 2x^3

at the point where x = a.

Answer: 8a - 6a^2

I have no idea how to answer this question since it doesn't give me any points to work with.

Any help would be greatly appreciated!
Thanks in advance!

Differentiate it





y' is also known as the gradient function. so when x = a, the gradient would be equal to? substitute x = a for all x values





therefore, the slope of the tangent is equal to