Question

If cos 9 alpha=sin alpha and 9 alpha<90°,then find the value of 5 tan alpha is

Answer 1

Answer:

cos 9 alpha = sin alpha

cos 9 alpha = cos (90 - alpha)

9 alpha= 90 - alpha

10 alpha =90

alpha = 9

therefore,

5 tan alpha = 5× tan× 9

= tan 45

= 1