1. fint the lines that are tangent and normal to the curve at (1,1)

im guessing that i have to use the definition of a derivative, and substitute f(x) and x in the equation with one, and solve it?

what about the normal line?

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- Mar 15th 2009, 02:25 PM>_<SHY_GUY>_<[SOLVED] tangent/normal lines
1. fint the lines that are tangent and normal to the curve at (1,1)

*im guessing that i have to use the definition of a derivative, and substitute f(x) and x in the equation with one, and solve it?*

*what about the normal line?* - Mar 15th 2009, 02:29 PMPlato
- Mar 15th 2009, 02:29 PMe^(i*pi)
Correct, take the first derivative of and solve

The normal is always perpendicular to the tangent and so the product of their gradients must be -1: where = the gradient at that point and

In both cases use the equation of a straight line formula:

where is a coordinate. In your case this is (1,1) - Mar 15th 2009, 02:41 PM>_<SHY_GUY>_<
- Mar 15th 2009, 02:44 PMe^(i*pi)