What is the equation of the tangent to each curve at this indicated value. f(x) = (x²-3)(x²+1); x=4

Question

anonymous · Answer

Do you know how to find the derivative of the function?

anonymous · Answer

yes, is that all i do ?

anonymous · Answer

Yes, find the derivative and then substitute the x-value you are given to find the slope at x=4. Then just use that as a slope and use it to find the equation of the line.

anonymous · Answer

Ohhh ! thanks :D

anonymous · Answer

Not a problem!

anonymous · Answer

so if m=4 what do i do from there?

anonymous · Answer

The formula for the tangent line of a function $f(x)$ at the point $(a, f(a))$ is given by:$$
y-f(a) = f'(a)(x-a)
$$

anonymous · Answer

The formula for the tangent line of a function $f(x)$ at the point $(a, f(a))$ is given by:$$
y-f(a) = f'(a)(x-a)
$$
Given that $a=4$ and $f(a)=(16-3)(16+1)$$$
y-(16-3)(16+1) = f'(4)(x-4)
$$