Question

Find the answer to cot(a) + 1/sin(a)

a) sin (a/2)
b) cos (a/2)
c) tan (a/2)
d) cot (a/2)

Answer 1

Answer:

cotA+1/sinA

=cosA/sinA+1/sinA

=(cosA+1)/sinA

=2cos²(A/2)/2sin(A/2)cos(A/2)

=cos(A/2)/sin(A/2)

=cot(A/2)

hence, d) cot(A/2) is the answer :)