Question

cos60°=cossquare30°-sinsquare30°=1/2​

Answer 1

Answer:

$the \: value \: of \: cos60 = \frac{1}{2} \\ \\ cos {}^{2} 30 - sin {}^{2}30 \\ \\ = (\frac{ \sqrt{3} }{2}) {}^{2} - ( \frac{1}{2} ) {}^{2} \\ \\ = \frac{3}{4} - \frac{1}{4} \\ \\ = \frac{2}{4} \\ \\ = \frac{1}{2} \\ \\ so. \: \: \: cos60 = cos {}^{2} 30 - sin {}^{2} 30 = \frac{1}{2}$

in this way we can solve this problem. we have only to put the values and we will get the answer.

please see the attachment