Question

If A and B are complementary angles and then cosA.cosecB =?

Answer 1

if A and B are complementary angle
then A=90-B
$\frac{ \cos(a) }{ \sin(b) } = \frac{ \cos(a) }{ \sin(90 - a) }$
$= \frac{ \cos(a) }{ \cos(a) } = 1$