Algebra
# Quadratic Discriminant

$f(x)=ax^2+bx+c$

If $b>10, 0<a<2, c=3$, how many times does the graph $y=f(x)$ cross the x-axis?

$y=x^2+bx+c$ touches the $x$-axis at some point and intersects the y-axis at $(0,9)$, find the absolute value of $b$.

If the curveFind the positive value of $k$ such that the quadratic equation $4x^2+kx+9=0$ has identical roots.