TLA Implicit Differentiation

Hello,

I have a problem here that I am somewhat unsure about:

"**Point (-1, 1) lies on the curve ** . **Use tangent line approximation to approximate the y-coordinate of the point where x = -1.01.**"

(A) 1.02

(B) 0.978

(C) 0.965

(D) 1.101

(E) 0.98

Here is my go at it:

First, use implicit differentiation to find the derivative:

Substitute (-1, 1) and solve for the tangent line:

Tangent line linear formula:

Use TLA approximation formula with a = -1.01:

So my guess would probably be A, or 1.02. Am I doing this right? (I could have made a mistake differentiating).

Thanks.

Re: TLA Implicit Differentiation

Quote:

Originally Posted by

**Biff**

The last expression in parentheses should be . I get y' = 2 and the answer is (E).

Re: TLA Implicit Differentiation

When I differentiate, I get:

At the point (-1,1), we have the slope:

Hence:

Re: TLA Implicit Differentiation

Quote:

Originally Posted by

**emakarov** The last expression in parentheses should be

. I get y' = 2 and the answer is (E).

That makes better sense, thanks.

Re: TLA Implicit Differentiation

Quote:

Originally Posted by

**MarkFL2**

Thanks Mark, I thought it might have been a differentiating mistake. Also, I see how the TLA equation isn't necessary.