Question

If A + B = 90° and \[\cos B = \frac{3}{5}\]  what is the value of sin A? 

Answer 1

We have: 

`A+B=90°` 

`Cos B=3/5` 

`A+B=90°`

⇒ `A=90-B`

⇒`Sin A=sin (90-B)` 

⇒` Sin A= Cos B` 

⇒ `sin A=3/5 [sin(90°-B)= cos B ]` 

Hence the value of sin A is `3/5`