Question

if Z=1+2i then find the value of Z^3 + 7Z^2 - Z + 16​

Answer 1

Answer:

ANSWER

We have,

z=1+2i

Since,

${z}^{2}$

3 +7z 2−z+16

Put the value of z

Therefore,

=(1+2i) 3 +(1+2i) 2 −(1+2i)+16=1+8i 3+6i(1+2i+1+4i2+4i−1−2i+16=1−8i+6i+12=2+1−4+2i+15 = 1−2i−12−3+2i+15 = 1 Hence, the value is 1.