Question

sin 4a = cos 5a then a =?​

Answer 1

Step-by-step explanation:

According to the question :

sin a = cos(90-a)

sin 5a= cos 4a

so, sin 5a = cos ( 90 - 4a)

5a = ( 90 - 4a )

5a + 4a = 90

9a = 90

so, a = 10

the value of a = 10