Question

Is there any simpler method to do this

Answer 1

Find the value of the expression
2x^3 + 2x^2 -7x + 72
at x = \[\frac{ 3 + 5\sqrt{-1} }{ 2 }\]

Answer 2

how did u arrive at this step ?

Answer 3

This is not any step but rather the question itself
This is the main question

Answer 4

if u knw complex numbers yes,

http://www.wolframalpha.com/input/?i=2%28%283%2B5i%29%2F2%29%5E3+%2B+2%28%283%2B5i%29%2F2%29%5E2+-7%283%2B5i%29+%2B+72

Answer 5

yeah it would be iota ok i will see the link

Answer 6

so you know how to do it :)
hint for complex :-
(cos theta +i sin theta )^n=cos n theta +i sin n theta

Answer 7

but changing to polar is a pain here, better to work it algebraically

Answer 8

answer is 4 the wolfram gives sth different

Answer 9

yep that right