The Student Room Group
Competition - post a photo you've taken of nature >>
Competition - post a photo you've taken of nature >>
Competition - post a photo you've taken of nature >>

Algebra of Complex Numbers Help

I'm having difficulty solving a maths question, I don't even know how to start to be honest. It's:

Given the equation z + 2iz =8 + 7i express z in the form a + ib

please note that z is the complex conjugate of z, I just wasn't sure how I should type it on here
Reply 1
Avatar for SH0405
SH0405
15
Original post by anoymous1234
I'm having difficulty solving a maths question, I don't even know how to start to be honest. It's:

Given the equation z + 2iz =8 + 7i express z in the form a + ib

please note that z is the complex conjugate of z, I just wasn't sure how I should type it on here


Let z = a + bi, giving z* = a - bi (the conjugate can be written z*). If you substitute these into the equation, collect like terms and compare coefficients, you should get to the answer.
(edited 8 years ago)
Original post by anoymous1234
I'm having difficulty solving a maths question, I don't even know how to start to be honest. It's:

Given the equation z + 2iz =8 + 7i express z in the form a + ib

please note that z is the complex conjugate of z, I just wasn't sure how I should type it on here


I'd try substituting z = a + ib and the complex conj as a - ib then what could you do?
Reply 3
Avatar for anoymous1234
anoymous1234
OP
Original post by SH0405
Let z = a + bi, giving z* = a - bi (the conjugate can be written z*). If you substitute these into the equation, collect like terms and compare coefficients, you should get to the answer.


but if i sub in a+ib and a-ib i can't express z in the form a+ib as I no longer have a z
Reply 4
Avatar for SH0405
SH0405
15
Original post by anoymous1234
but if i sub in a+ib and a-ib i can't express z in the form a+ib as I no longer have a z


That's the whole point. You need the values of a and b in order to be able to express z in that form.

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you