1.

If z = 2 − i√7 , then show that 3z3 – 4z2 + z + 88 = 0.

Answer»

Given z = 2− i√7

⇒ z – 2 = − i√7

⇒ (z – 2)2 = (− i√7)2

⇒ z2 – 4z + 4 = 7i2

⇒ z2 – 4z + 4 = – 7

⇒ z2 – 4z + 11 = 0

3z3 –4z2 + z + 88 = 3z(z2 – 4z + 11) + 8z2 – 32z + 88

= 3z(0) + 8(z2 – 4z + 11) = 0 + 8(0) = 0

∴ 3z3 – 4z2 + z + 88 = 0



Discussion

No Comment Found

Related InterviewSolutions