What is the largest positive integer value of m such that the equation:
3x^2-mx+21=0
has no real solutions?
In the Quadratic FORMULA
\(x = {-b \pm \sqrt{b^2-4ac} \over 2a}\)
b^2 - 4ac is called the discriminant if this is a NEGATIVE value ( <0) then there will be no real solutions
b^2 - 4ac < 0
m^2 - (4)(3)(21) < 0
m^2 < 4 * 3 * 21
m^2 < 252
m < 15.87 ( since we are only looking for POSITIVE integers)
then the largest positive integer for m would be 15