Q26Long answer
Find the value of the expression cos 4 + cos 4 + cos 4 + cos 4 8 8 8 8 4 π 4 3π [Hint: Simplify the expression to 2 ( cos + cos ) 8 8 π 3π π 3π =2 cos 2 + cos 2 − 2cos 2 cos 2 8 8 8 8 TRIGONOMETRIC FUNCTIONS 55
Find the value of the expression cos 4 + cos 4 + cos 4 + cos 4 8 8 8 8 4 π 4 3π [Hint: Simplify the expression to 2 ( cos + cos ) 8 8 π 3π π 3π =2 cos 2 + cos 2 − 2cos 2 cos 2 8 8 8 8 TRIGONOMETRIC FUNCTIONS 55