सत्यापित करो कि ` cos 60^(@) =cos^(2) 30^(@) -sin^(2) 30^(@)=(1)/(2)`

Explanation

दिया है ,
`RHS = cos^(2) 30^(@) -sin^2 30^(@)=((sqrt(3))/(2))^(2)-((1)/(2))^(2)=(3)/(4)-(1)/(4)=(2)/(4)=(1)/(2)`
तथा , `LHS = cos60^(@)=(1)/(2)`
`:.` LHS=RHS
अतः ` cos 60^(@) = cos^(2) 30^(@) - sin^2 30^(@) =(1)/(2)`