1.

A+B = 90^(@) rArr cos A cos B in

Answer»

`[ - (1)/(3) , (1)/(3) ]`
`[ - (1)/(2) , (1)/(2)]`
`[ - (1)/(4) , (1)/(4)]`
`[ - (3)/(4) , (3)/(4)]`

ANSWER :B


Discussion

No Comment Found