Question

cos3x + cosx - Cos2x = 0
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Answer 1

Answer:

Step-by-step explanation:

cos3x+cosx−cos2x=0

⇒2cos2x.cosx−cos2x=0

⇒2cos2x.cosx−cos2x=0

⇒cos2x(2cosx−1)=0

⇒cos2x=0or cosx=12

⇒2x=(2n+1)π2

or cosx=cosπ3,n∫I

⇒x=(2n+1)π4 or x=2nπ±π3, n∫I. Ans.