Question

sin 60° - 3 tan 30° + 5 cos 90°
cos2 45°​

Answer 1

Answer:

Step-by-step explanation:

Sin 60 = √3/2

tan 30= 1/√3

Cos 90 =0

Cos 45= 1/√2

And cos(2x) = cos^2(x) - sin^2(x) = 2 cos^2(x) - 1 = 1 - 2 sin^2(x)

Putting values we get cos2 45 as -1/2