Question 119

$$\cos \frac{2 \pi}{6} + \sin \frac{5 \pi}{6} =$$

Solution

we can write this

cos60 + sin150 = equation 1

and sin150 = sin( 90 + 60)

= sin90co60 + cos90sin60

put sin90 = 1 and cos60 = 1\2

we get

sin150 = 1\2 and cos 60 = 1\2 put value in equation 1

cos60 + sin150 = 1\2 + 1\2 = 1 Answer

Create a FREE account and get: