If a and 4a+3b+2c have same sign. Then, ax2+bx+c=0,(a≠0) cannot have both roots belonging to
Let a,b,c be real numbers with a ≠ 0. Suppose a and 4a + 3b + 2c have the same sign. Then equation ax2 + bx + c = 0 cannot have both the roots in the interval.