How do I find the equation of the tangent line to the graph of: f(x)=3-2x^2 at the point (-2,-5)??

Question

How do I find the equation of the tangent line to the graph of: f(x)=3-2x^2   at the point (-2,-5)??

.sam. · Answer

Find f '(x)
then substitute x=-2 into f '(x)
then you can find the value of f '(x),thats the value of the slope, or "m" or gradient,
then create new equation,
$$y-y _{1}=m(x-x _{1})$$ using points (-2,-5)

anonymous · Answer

f'(x) is -4x  substitute x=-2 into f'(x)=(-4)(-2)=8 so the slope is +8?

.sam. · Answer

yes

.sam. · Answer

then create new equation,

anonymous · Answer

i got y=8x+11 as my new equation. is that right?

anonymous · Answer

Yep, it's called tangent line!

anonymous · Answer

@Quyen, I think you're new! Could you click on the blue Best Answer after you're happy with the solver!

anonymous · Answer

haha i am. but sure!!

anonymous · Answer

Are you VNmese!

anonymous · Answer

yess, i am!

anonymous · Answer

I mean medal for Sam, because he is the one instructed you the whole way!

anonymous · Answer

i clicked on his already. :)

anonymous · Answer

What grade are you? are you taking Calculus?

anonymous · Answer

junior year... honors calc online... not going so well.. :/

anonymous · Answer

Stick to this site for at least the weekend for month, your grade will surely improved!

anonymous · Answer

Why do you take online? It's tough :(

anonymous · Answer

definitely will. the way you guys explain it on here is a lot easier to understand than my online notes. but b/c they don't offer it at my school.

anonymous · Answer

Hey, jump to your question now, the solver's waiting!