Question

Find the value of the following expression:

cos² 45° + sin² 60° + sin² 30°

Answer 1

Given: `cos 45^circ = sqrt(2)/2, sin 60^circ = sqrt(3)/2, sin 30^circ = 1/2`.

⇒ `cos^2 45^circ = (sqrt(2)/2)^2`

= `2/4`

= `1/2`

`sin^2 60^circ = (sqrt(3)/2)^2`

= `3/4`

`sin^2 30^circ = (1/2)^2`

= `1/4`

Sum = `1/2 + 3/4 + 1/4`

= `1/2 + 1`

= `3/2`