If cos x = k has exactly one solution in [0, 2 π], then write the value(s) of k.

Question

Philoid · Accepted Answer

As cos x = cos θ

Then x=2nπ ± θ

And it is said that it has exactly one solution.

So θ=0 and

=nπ

In the given interval taking n=1,x=π {n=0 is not possible as cos 0 = 1 not -1 but cos π is -1}