Q5 of 142 Page 11

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

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}


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