4-1.Complex numbers
medium

If $z =2+3 i$, then $z ^{5}+(\overline{ z })^{5}$ is equal to.

A

$244$

B

$224$

C

$245$

D

$265$

(JEE MAIN-2022)

Solution

$z^{5}+(\bar{z})^{5}=(2+3 i)^{5}+(2-3 i)^{5}$

$=2\left({ }^{5} C_{0} 2^{5}+{ }^{5} C_{2} 2^{3}(3 i)^{2}+{ }^{5} C_{4} 2^{1}(3 i)^{4}\right)$

$=2(32+10 \times 8(-9)+5 \times 2 \times 81)=244$

Standard 11
Mathematics

Similar Questions

Start a Free Trial Now

Confusing about what to choose? Our team will schedule a demo shortly.