Algebra(1st one was typo)
posted by Jacob .
The function f(x)=x^3 +1/4 x −1^4 is a monotonically increasing function, hence it is injective (onetoone), so its inverse function exists and is well defined. How many points of intersection are there, between the function f(x) and its inverse f^−1 (x) ?

so is this one,
try doing it the way I did it in your original post