Let z be a complex number such that the imaginary part of z is non-zero and a=z2+z+1 is real. Then, a cannot take the value
−1
13
12
34
The roots of the equation a=z2+z+1 are non-real z2+z+1−a=0⇒z=−1±√(4a)−32 For z do not have real roots, 4a−3<0⇒a<34
Let z be a complex number such that the imaginary part of t is non zero and a = z2+z +1 is real.Then a cannot take the value