Question

(cosec A - sin A) (sec A - cosA ) (tan A+ cot A)= 1

Answer 1

(1/sin-sin)(1/cos-cos)(tanA+cotA)
(1-sin^2/sin)(1-cos^2/cosA)(tanA+cotA)
(cos^2/sin)(sin^2/cos)(sinA/cosA+cosA/sinA)
cousin(sinA/cosA+cosA/sinA)
cos^2+sin^2=1
proved..
hope ,it is helpful