cot^-1(2tan(cos^-18/17))+tan^-1(2tan(sin^-18/17))=tan^-1300/161

Answer 1

the cos^-18/17 and the sin^-18/17 in your expression don't make sense

did you mean cos^-1 (18/17) ?
in that case, that would be undefined, since no angle exists such that cosØ = 18/17
same thing would be true for the sine part