Question

by using the method of completing the square show that the equation 2x square +x+4 has no real roota

Answer 1

2x2 + x -4=0 2x2 + x = 4 x2 + x/2 + 1/4 = 2+1/4 (x + 1/2)2 = 9/4 (x + 1/2) = ± 3/2 x = 3/2 - 1/2 = 1 or x = 3/2 + 1/2 = 2 Hence, x = 1 or 2.