Re: Tangent Line in Point..

Rewrite the tangent line as , so you can see that the tangent line has gradient = -2.

This means the derivative of your curve must be -2. So take the derivative, set it equal to -2, solve for x, then substitute this value into the equation for the curve to find y.

Re: Tangent Line in Point..

But now how can i find the value of "C"?

Quote:

Originally Posted by

**Prove It** Rewrite the tangent line

as

, so you can see that the tangent line has gradient = -2.

This means the derivative of your curve must be -2. So take the derivative, set it equal to -2, solve for x, then substitute this value into the equation for the curve to find y.

Re: Tangent Line in Point..

You don't need to find the value of c. It is a parameter. Your point of tangency will be in terms of c and d.

Re: Tangent Line in Point..