How do you know there is no real solution to the quadratic equation x2+x+14=0?
2 answers
because the discriminant (b^2-4ac) is negative.
The easiest way to justify this is to visualize the graph. We know from the first the signs of this equation that this quadratic opens upwards and know that it is shifted to be above the x-axis, so the quadratic never crosses the x-axis and therefore has no roots.
You could justify this by finding the discriminant, sqrt(b^2 - 4ac). Since this answer would yield a negative number, both roots lie in the complex plane.
You could justify this by finding the discriminant, sqrt(b^2 - 4ac). Since this answer would yield a negative number, both roots lie in the complex plane.