Question

Find the value of cos 30° − sin 60
a) 1
b) 0
c) 2
d) −1​

Answer 1

Answer:

The exact value of cos(30)° is √3/2 . The exact value of sin(60)° is √3/2 .

so, cos30° - sin 60°= √3/2 -√3/2 =0

Answer 2

Solution :-

cos30° - sin60°

♦ Method 1 :-

As we know that ,

cosx = sin(90° - x)

So ,

Let x be 30°

• cos30° = sin(90° - 30°) = sin60°

Now substituting cos30° = sin60°

☞ sin60° - sin60°

☞ 0

♦ Method 2 :-

cos30° - sin60°

Substituting ,

• cos30° = √3/2
• sin60° = √3/2

☞ √3/2 - √3/2

☞ 0

Hence , cos30° - sin60° = 0