List of top Mathematics Questions on Functions asked in JKCET

Which of the following functions is inverse of itself?

The mapping $ f : N \to N $ given by $ f(n) = n^3 + 3, n \in N $ where $ N $ is the set of natural number, is

The function is $ f(x)=\frac{1}{2-\cos \,3x},\,x\,\in \left[ 0,\frac{\pi }{3} \right], $ is