tan^2(45·-30·/2)

Are those dots meant to be degree signs?

If so then

 

tan^2(45·-30·/2)

 

\(tan^2(45-30/2)\\=tan^2(45-15)\\=tan^2(30)\\ = (\frac{1}{\sqrt3})^2\\=\frac{1}{3}\)