Question

How do you evaluate `cos(-pi/6) cos (pi/4)`?

Answer 1

`sqrt6/4`

Explanation:

Trig table -->
`cos (pi/4) = sqrt2/2`
`cos (-pi/6) = cos (pi/6) = sqrt3/2`
`P = cos (pi/4).cos (-pi/6) = (sqrt2/2)(sqrt3/2) = sqrt6/4`