Question

(cos 0° +sin 45° +sin 30°)(sin 90° – cos 45° +cos 60°)​

Answer 1

$(cos0 + sin45 + sin30)(sin90 - cos45 + cos60) \\ \\ = (1 + \frac{1}{ \sqrt{2} } + \frac{1}{2} )(1 - \frac{1}{ \sqrt{2} } + \frac{1}{2} ) \\ \\ = ( \frac{3}{2} + \frac{1}{ \sqrt{2} } )( \frac{3}{2} - \frac{1}{ \sqrt{2} } ) \\ \\ = ( { \frac{3}{2} })^{2} - ( { \frac{1}{ \sqrt{2} } })^{2} \\ \\ = \frac{9}{4} - \frac{1}{2} \\ \\ = \frac{9 - 2}{4} \\ \\ = \frac{7}{4}$