Question

Prove that
(cos²A-1) (COT²A+1) =-1​

Answer 1

Step-by-step explanation:

(cos^2-1)(cot^2+1)

=(Cos^2-1)(cos^2/sin^2 +1)

=(cos^2-1)(cos^2+sin^2/sin^2)

=(cos^2-1)(1/sin^2)

=-(1-cos^2)(1/sin^2)

=(-sin^2)/(sin^2)

=-1

hence proved