Question

cosA=0
find the value of
(a) 1-tan^2A/1+tan^2A
(b) sin A (3) cotA-sinA
​

Answer 1

cos A = 0., A=90°

so.,

a) 1- tan^2*90/1+tan^2*90

1-0=1(-tan and +tan get cancelled)

answer is 1.,

b)sin 90(3)*cot 90-sin 90.,

sin 270*0-1; 1*(-1)., -1.

answer is -1.