# How do you find the equation of the tangent to the curve #x=t^4+1#, #y=t^3+t# at the point where #t=-1# ?

##### 1 Answer

To find the equation of the tangent line, we need the slope

Then the equation is the usual

We have the parametric curve

so we compute

The chain rule

So we use the derivatives of the parametric equations:

Also at

Now we put in the info for the tangent line:

\ Another great answer from the modest dansmath! /