JEE Advance - Mathematics (1998 - No. 38)
Let $$h\left( x \right) = f\left( x \right) - {\left( {f\left( x \right)} \right)^2} + {\left( {f\left( x \right)} \right)^3}$$ for every real number $$x$$. Then
$$h$$ is increasing whenever $$f$$ is increasing
$$h$$ is increasing whenever $$f$$ is decreasing
$$h$$ is decreasing whenever $$f$$ is decreasing
nothing can be said in general.