1.

If cos alpha+ cos beta= a, sin alpha+ sin beta= b and alpha- beta= 2 theta. Then (cos 3 theta)/(cos theta)=

Answer»

`a^2+B^2-2`
`a^2+b^2-3`
`3-a^2-b^2`
`(a^2+b^2)//4`

ANSWER :B


Discussion

No Comment Found