The function \[y = 2x^3 - 6x^2 + 5x - 7\] has
no stationary points;
one stationary point;
two stationary points;
three stationary points.
Differentiating, we find \[y' = 6x^2 - 12x + 5.\]
We could find the roots, but it is quicker just to notice that the discriminant of the quadratic \(y'\) is \(12^2 - 4\times 6\times 5 = 24 > 0\).
This means the equation \(y' = 0\) has two distinct real roots, and hence the answer is (c).
