Thread: Chain Rule, and Power Rule

Can anyone help me out... I know that on problem like you find the derivtive of those using simple differentiation, and them combine and so on.

However, I'm not sure how to do this: find the equation of a tangent line to the graph of f using x=-2 on an equation of

I thought that was the derivative, how can this be accomplished. Simply plugging in -2 did not work. .

I'm confused a bit by your wording. Are you saying f(x)=6x^2..... and you need to find the tangent line to f(x) at x=-2?

Sorry, I should of said: Find an equation for the tangent line to the graph f at x=-2

Ok, so

Plugging in x=-2 gives you the y-value of this point on the function. So you'll have a point (-2, f(-2)).

Now take the derivative of f(x) and plug in -2 to find the slope of the tangent line at x=-2.

Now you have a point and a slope, thus a line can be formed!

Point-slope formula:

is the point on the graph you found and m is the slope at x=-2.

Make sense?

How can the derivitive of this function be solved using the chain or power rule?

Ok so . We have a product here, thus the product rule, and the second term is a composite expression thus the chain rule is needed.



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