Question

solve this maths problem... On notebook ​

Answer 1

$HEYA \: \\ \\ \cos(x) = \cos {}^{2} (x \div 2) - \sin {}^{2} (x \div 2) \\ and \\ (1 - \sin(x) ) = ( \cos(x \div 2) - \sin(x \div 2) ) {}^{2} \\ \\ \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: ( \cos {}^{2} (x \div 2) - \sin {}^{2} (x \div 2) ) \\ \: \: \: tan {}^{ - 1} \: \: \: \: - - - - - - - - - - - \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: ( \cos(x \div 2) - \sin(x \div 2) ) {}^{2} \\ \\ \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: ( \cos(x \div 2) + \sin(x \div 2) ) \\ \: \: \: tan {}^{ - 1} \: \: \: \: \: - - - - - - - - - \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: ( \cos(x \div 2 ) - \sin(x \div 2) ) \\ \\ tan {}^{ - 1} (tan \: (45 + x \div 2)) \\ \\ = 45 + x \div 2$