confirmation on complex numbers
the question is; solve
z^2 + (2+4i)z -11 -2i = 0
well i did it and my answer is z= 6 + 2i and z= -6 -2i which i know is WRONG right?
BUT say if it is CORRECT, is that my final answer? or do i have to sub that in with something because i am sure you have to.
So can someone give me the correct answer and the steps involve as well as i want to crack this thing once and for all.
Re: confirmation on complex numbers
Quote:
Originally Posted by vixity
the question is; solve
z^2 + (2+4i)z -11 -2i = 0
well i did it and my answer is z= 6 + 2i and z= -6 -2i which i know is WRONG right?
BUT say if it is CORRECT, is that my final answer? or do i have to sub that in with something because i am sure you have to.
So can someone give me the correct answer and the steps involve as well as i want to crack this thing once and for all.
The correct answer is
z = 2 - i
and
z = -4 -3i
EDIT:
Hang on there while I try to find a useful link...
Re: confirmation on complex numbers
Re: confirmation on complex numbers
Quote:
Originally Posted by krtxmrtz
The correct answer is
z = 2 - i
and
z = -4 -3i
EDIT:
Hang on there while I try to find a useful link...
yeah and what do you do now with the two answers for z. Do you sub it in the question?cause if you do you solve for i correct?
Re: confirmation on complex numbers
The answers for z are the answers to the whole question. i is a constant, you can't solve for it.
Re: confirmation on complex numbers
And just to be sure it is clear, i is used to indicate imaginary numbers. It is defined as sqrt(-1). So you can't "solve" for it, it would be like solving for 6.
zaza
Re: confirmation on complex numbers
And, as a math teacher I had used to say, if you don't know how to calculate sqr(-1) then what you do is
"you call the problem the solution", so sqr(-1) = i and that's all there is to that.