Question

(cos 0° + sin 30° + sin 45°)(sin 90° + cos 60° – cos 45°) = ?

Options

• `7/4`

• `5/6`

• `3/5`

• `5/8`

Answer 1

`bb(7/4)`

Explanation:

Given expression = `(1 + 1/2 + 1/sqrt(2))(1 + 1/2 - 1/sqrt(2))`

= `(3/2 + 1/sqrt(2))(3/2 - 1/sqrt(2))`

= `{(3/2)^2 - (1/sqrt(2))^2}`

= `(9/4 - 1/2)`

= `7/4`