Find the equation of the line tangent to the graph of at the point . Leave your answer in the form .

I just want to verify if what I'm doing is correct... It has been awhile since I have done one of these.

I assumed I should use the equation

Which gave me:

Here is where I have trouble... I am unsure of the fifth root of -1. I have seen that it could be complex, or it could be 1... And I just can't verify it myself. I'm sure it is easier than I am making it out to be, but any help would be appreciated.