I have to find the points at which the graph of F either has a horizontal or vertical line.
the function is F(x)=4x^(3/4)-2
Draw the graph. The domain is [0, oo) (why?). It's an increasing function. The tangent is a vertical line at (0, -2) (why?) with equation x = 0. There's no point on the graph at which the tangent is horizontal (why?).