(iv) 2x2+x+4=0
On comparing this equation with ax2+bx+c=0, we get
a = 2, b = 1 and c = 4
By using quadratic formula, we get
x=−b±√b2−4ac2a
⇒x=−1±√(1)2−4×2×42×2
⇒ x=−1±√1−324
⇒ x=−1±√−314
The square of a number can never be negative.
∴ There is no real solution of this equation.