Tg^2x+ctg^2x+2-1/cos^2x

Question

Tg^2x+ctg^2x+2-1/cos^2x

Answer 1

Tg²x+ctg²x+2-1/cos²x=tg²x+ctg²x+2-(1+tg²x)=tg²x+ctg²x+2-1-tg²x=1+ctg²x=1/sin²x