Question

A.Verify the identity.
B.Determine if the identity is true for the given value of x. Explain.


Sec(x) / tan(x) = tan(x) / [tan(x) – cos(x)],x = π


I already solved A and I believe it's true; however, I need help with B.

Answer 1

clearly B is false at x=π

Sec(x) / tan(x) = tan(x) / [tan(x) – cos(x)]
(-1)/0 = 0/(0-(-1)) = 0/1
-∞ = 0

I don't think so!