I'm learning gradient descent method and I saw different (and opposite) things on my referrals.
I have the following function
$$f(x) = 2x^2 - 5x$$
and I have to calculate some iterations of gradient descent from $x_0 = 1$. So, I calculate the function at $x_0$, the derivative of the function at $x_0$ and now I have to apply the formula
$$x_1 = x_0 - \alpha \cdot f'(x_0)$$
Is $\alpha$ randomly chosen or do I have to force the formula to $0$ value? I'm quite confused.