Question

Evaluate each of the following:

( cos 0°+sin 45°+sin 30° ) ( sin 90° - cos 45° + cos 60° )

Answer 1

Given: 

(cos 0°+sin 45°+sin 30°) (sin 90° - cos 45° + cos 60°) 

To find: The value of the above. 

Solution:  Use the formulas:

Solve,

( cos 0°+sin 45°+sin 30° ) ( sin 90° - cos 45° + cos 60° )

Use the identity: (a-b) (a+b) = a²-b²