Question

(x) cos 2.xº + cosx
º - 2 = 0​

Answer 1

Answer:

Step-by-step explanation:

Consider the curves y=cos2xcosx and y=x.

The number of solutions of this equation is same as the number of points where these two curves intersect. We observe that y=cos2−cosx is a continous curve in [0,π/2] and remains below x-axis whereas y=x remains above x-asis. These two curves cut at (0,0). Hence, the equation cos2x−cosx=x has exactly one solution in [0,π/2]