Question

Having trouble with this.
Find the equation of the tangent.
f(x)=x^2-2; a=4

Answer 1

To find the equation of the tangent, you first need to find the slope of the tangent line. THhe slope fo the tangent is found using the derivative.

f'(x)=2x
f(4)=8.

So, the slope of the tangent line is 8.

Now, for the equation of the line, you need a point. By plugging 4 into your original function, you can get the tangent point to the curve.

f(4)=16-2=14
so (4,14) is the tangent point.

So, use y-b=m(x-a) to get your tangent line equation using (4,14) as (a,b) and m=8.

Answer 2

Ohhhhhhh. I kept using 2 from f'(x) as my slope. Thank you. Clears everything up.

Answer 3

That would make quite the difference. :) Glad I could help.