`cos x = cos 60^(@) cos 30^(@) + sin 60^(@) sin 30^(@) ` में x का मान ज्ञात करो ।

Explanation

दिया है :
` cos x = cos 60^(@) cos 30^(@)+ sin 60^(@) sin 30^(@) `
`implies cos x =(1)/(2) xx (sqrt(3))/(2) +(sqrt(3))/(2) xx (1)/(2)`
`implies cos x =(sqrt(3))/(4) +(sqrt(3))/(4)`
`implies cos x =(sqrt(3))/(2)`
`implies cos x = cos 30^(@) implies x=30^(@)`