Question

please answer me ...​

Answer 1

Answer:

Hi mate !!

Here's your answer !!

We know the identity that,

Sec Ф = Cosec ( 90 - Ф )

=> Sec ( 4a + 40 ) = Cosec a

= Sec ( 4a + 40 ) = Sec ( 90 - a )

Sec gets cancelled on both sides. After that we get,

= 4a + 40 = 90 - a

= 4a + a = 90 - 40

→ 5a = 50

=> a = 50 / 5 = 10

Hence a = 10°.