2sec^20 - sec^40 - 2cosec^20 + cosec^40 = cot^40 - tan^40 '0' is theta .

Pls help me out with this

From the RHS:

Cot^4θ-tan^4θ

=(cos^2θ/sin^2θ)*(cos^2θ/sin^2θ)-(sec^2-1)*(sec^2-1)

=(1-sin^2θ)/(sin^2(θ))*(1-sin^2θ)/(sin^2(θ))-(sec^4θ+2sec^2θ+1)

=(cosec^2θ-1)*(cosec^2θ-1)-sec^4θ+2sec^2θ-1

=cosec^4θ-2cosec^2θ+1-sec^4θ+2sec^2θ-1

=cosec^4θ-2cosec^2θ-sec^4θ+2sec^2θ

=LHS

Step-by-step explanation:

(a) the volume of the cone is 20/3 in3

hence, option a is correct.