Question

It's a prove that...

2sin70.cos20=sin90+sin50​

Answer 1

Explanation:

As we have,

2sinxcosy = sin(x + y) + sin(x - y)

`=2sin70cos20\\\\=sin(70 + 20) + sin(70 - 20)\\\\=sin90 + sin50`

Hence, LHS=RHS

Answer 2

LHS = RHS

`2sinxcosy = sin(x + y) + sin(x - y)`

`= 2sin70cos20`

`= sin (70+ 20) + sin(70 - 20)`

`=sin90+ sin50`

Hence, Proved