How to prove that the binary function image intersects with the positive and negative semi-axes of the X axis?
It is proved that the image of quadratic function f(x) intersects with the positive and negative semi-axes of X axis. Two conditions must be met: 1, quadratic equation f(x)=0 has two different real roots; 2. Two root symbols. So the discriminant with roots? =b? -4ac & gt; 0; x 1x 2 = c/a & lt; 0。