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A hint to get started

Distinguish a modulus square from a complex square

(a) The complex numbers z,wz,w satisfy z+w∗+5i=10z+w^*+5i=10 and ∣w∣2=z+18+i|w|^2=z+18+i. Find zz and ww. marks

(b)(i) Given that 2+i2+i is a root of z2−5z+7+i=0z^2-5z+7+i=0, find the second root in Cartesian form, showing your working. marks

(b)(ii) Hence find the roots of −iw2+5w+7i−1=0-iw^2+5w+7i-1=0. marks

[2017/CJC/II/4(a),(b)]

CJC · Review problems · Question 9

Write the modulus square as a²+b², a real number, and the conjugate as a−bi.

Read the worked solution