Find the root of the complex 3+4i

What we should know is that the root 3+4i is a complex number that looks alot like a+bi.

We can say : rt(3+4i) = a+bi (Where we dont know what a & b is..yet)

and when we square both sides (rt(3+4i))^2=(a+bi)^2 | 3+4i = (a+bi)^2

we get 3+4i = a^2+2abi-b^2

We seperate the Real and Imaginary parts to get a simultainus equation

3 = a^2-b^2

4 = 2ba

if this is solved we get a= (+-)2 and b =(+-)1

to get (+-)(2+i) <--- which is the answer

AA
Answered by Ade A. Further Mathematics tutor

3129 Views

See similar Further Mathematics A Level tutors

Related Further Mathematics A Level answers

All answers ▸

How would you use the Integration Factor method to solve an ordinary first-order linear differential equation?


Write down the equations of the three asymptotes and the coordinates of the points where the curve y = (3x+2)(x-3)/(x-2)(x+1) crosses the axes.


What is the value of x from (x+2)^2=4


In simple harmonic motion, where would the object have the largest speed. If the angular velocity is 2 rad s^-1, and the amplitude is 1m, what is the largest speed obtained by the object?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences