Division of complex numbers
My answer to the first one is 3i/-9 + -3/-9 but i am pretty sure that its wrong. Can someone show me how to do these correct?
Please help!
1. z1 = 1-i and z2 = 3i z1/z2 = ?
( 1 -i) / (3i) * (3i) / (3i) =
(1 -i) (3i) / 9i^2 =
(1 -i)(3i) / -9 =
( i -1)(3i) / 9 =
3i^2/ 9 - 3i/9 =
-3/9 - i/3 =
-1/3 - i/3
2. z1 = 1+2i and z2 = 1+i z1/z2 = ?
(1 + 2i) / (1 + i) * (1 -i) / (1 - i) =
(1 + 2i)(1- i) / (1 - i^2) =
(1 + 2i)(1- i) / (1 - -1) =
(1 + i -2i^2) / 2 =
(1 + i + 2) / 2 =
(3 + i) /2=
3/2 + i/2
BTW...you can go here http://www.wolframalpha.com/input/?i=%281+%2B+2i%29+%2F+%281+%2B+i%29
and evaluate these...just click into any box and type in your complex ratios....it will simplify them for you....!!!
{I checked both answers using this site....}
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1. z1 = 1-i and z2 = 3i z1/z2 = ?
( 1 -i) / (3i) * (3i) / (3i) =
(1 -i) (3i) / 9i^2 =
(1 -i)(3i) / -9 =
( i -1)(3i) / 9 =
3i^2/ 9 - 3i/9 =
-3/9 - i/3 =
-1/3 - i/3
2. z1 = 1+2i and z2 = 1+i z1/z2 = ?
(1 + 2i) / (1 + i) * (1 -i) / (1 - i) =
(1 + 2i)(1- i) / (1 - i^2) =
(1 + 2i)(1- i) / (1 - -1) =
(1 + i -2i^2) / 2 =
(1 + i + 2) / 2 =
(3 + i) /2=
3/2 + i/2
BTW...you can go here http://www.wolframalpha.com/input/?i=%281+%2B+2i%29+%2F+%281+%2B+i%29
and evaluate these...just click into any box and type in your complex ratios....it will simplify them for you....!!!
{I checked both answers using this site....}
Can you explain the first one please?
The second one is correct but I cant seem to get the first one right:
( 1 -i) / (3i) * (3i) / (3i) = (should it not be (1-i)(-3i) / (3i)(-3i) because of conjugate?)
1)
$$\\\frac{1-i}{3i}\times\frac{i}{i}=\frac{(1-i)i}{3i^2}=\frac{i-i^2}{3*-1}=
\frac{i--1}{-3}=\frac{i+1}{-3}=\frac{-1-i}{3}=-\frac{1}{3}-\frac{i}{3}$$
There is no conjugate on the second one compare it to surds for it is much the same
rationalize the denominator
$$\\\frac{6}{2\sqrt5}=\frac{6}{2\sqrt5}\times\frac{\sqrt5}{\sqrt5}=
\frac{6\sqrt5}{2*5}=\frac{6\sqrt5}{10}=\frac{3\sqrt5}{5}\\\\\\
BUT\\\\
\frac{6}{2+\sqrt5}=\frac{6}{2+\sqrt5}\times\frac{2-\sqrt5}{2-\sqrt5}=\;\;etc$$