Question

without using mathematical tables find the value of x if cosx=cos60.cos30+sin60.sin30

Answer 1

Answer:

Take this answer.

Step-by-step explanation:

Cos 60 =1/2

Cos 30 =√3/2

Sin 60 =√3/2

Sin 30 =1/2

By putting these values in your question,we get :

X= 1/2*√3/2+√3/2*1/2

X= √3/4+√3/4

X= 2√3/4

X= √3/2

X= Cos^-1(√3/2)

But cos x = cos 30°,as cos 30° is √3/2

Therefore x=30°.