tangent line on ti nspire

Forum Attachments

Summary:

How to find the equation

tangent line on ti nspire

sam (guest) 21 Nov 2015 02:24

How would you go about doing this on ti nspire cx cas:

Find the equation of the line that is tangent to the curve
y=5xcosx
at the point (π,−5π).

The equation of this tangent line can be written in the form y=mx+b where

m=

and b=

Re: tangent line on ti nspire

jonbush 21 Nov 2015 06:45

Find the derivative of y with respect to x at x=π. Then you can write out the equation in y=mx+b form and solve for b with the point.

Re: tangent line on ti nspire

Prinz Azir 30 Nov 2015 23:40

Simply press menu, 4, 9, then plug it in like so:
tangentLine(5*x*cos(x),x,π)

DO NOT FORGET THE COMMAS. Or the multiplication signs - if you simply type xcosx, your calculator will not recognize the input.

Re: tangent line on ti nspire

jonbush 01 Dec 2015 00:01

Prinz Azir,
Welcome to TI|BD! It is good to have someone knowledgeable about the TI Nspire in our community. If you have not already, consider introducing your self in the Community Introductions thread.