Question

cos square 75+sin square 75+cosec square 80-cot square 80.

solve it.​

Answer 1

sin^2(75)+cos^2(75)+cosec^2(80)-cot^2(80)=

=sin^2(x)+cos^2(x)=1 by properties

so we can write

1+cosec^(80)-cot^2(80)

=cosec^(x)=1+cot^2(x) by properties

so cosec^2(x)-cot^2(x)=1

=1+1 {cosec^2(80)-cot^2(80)=1}

=2