Hey guys, my teacher gave me these two problems which have been keeping me up all night:

Prove:

[2tan^-1 (1/3) ]+ [tan^-1(1/7)] = pi/4

and

Find all values of θ:

Tan (π cot θ) = cot (π tan θ)

My classmates and I have been kinda stumped... Any help is much appreciated

Sincerely,

Carlos Jesena