Friday

December 19, 2014

December 19, 2014

Posted by **Anne** on Thursday, March 13, 2008 at 7:15am.

W=(Z+1)/(1-Z)

what is W if Z=1.5i?

thanks for the help!

- Calculus -
**drwls**, Thursday, March 13, 2008 at 8:04amSubstitute 1.5i for Z in the equation.

W = (1 + 1.5i)/(1 - 1.5i)

This can be simplied by multiplying numerator and denominator by 1 + 1.5i. It gets rid of the complex deniminator. W = (1 + 1.5i)^2/(1 + 1.5)^2)

= (1/3.25)* (1 + 3i -2.25)

= (4/13)(-1.25 + 3i)

= -5/13 + 12i/13

- Calculus -
**Anne**, Thursday, March 13, 2008 at 8:24amah!!i was so dumb! i was trying to multiplying numerator and denominator by 1+Z,of course it didnt work out...haha...

thankyou !!!!

- Calculus -
**Reiny**, Thursday, March 13, 2008 at 8:44amAnne, you were not so dumb at all!

I solved the above question the same way by multiplying top and bottom by 1+Z.

Whether you substitute first and then multiply like drwls did, or multiply first and then substitute does not matter, you should get the same result.

I had (3i-1.25)/(13/4)

= (12i-5)/13 which is also drwls' answer

Check your work, you must have made an error.

- Calculus -
- Calculus -
**Anne---?**, Thursday, March 13, 2008 at 9:53amyeah...i did made an error...

3.35 instead of 3.25...haha.

thx guys!

**Answer this Question**

**Related Questions**

Maths- complex numbers - Find tan(3 theta) in terms of tan theta Use the formula...

Complex numbers - quadratic formula - Let a and b be real numbers. The complex ...

Calculus--complex numbers - the complex number Z satisfies Z/(Z+4)= 3+2i Find Z...

math-complex numbers - Sketch the sets of complex numbers in the complex plane ...

Complex Numbers - The system of equations |z - 2 - 2i| = \sqrt{23}, |z - 8 - 5i...

math-complex numbers - If z = -3+4i, determine the following related complex ...

calculus - can you please explain tep by step how to solve dividing complex ...

Math - I am in the 5th grade and my homework tonight is about complex numbers. I...

Pre-cal - The equation of the line joining the complex numbers -5 + 4i and 7 + ...

Precalculus - Let z and w be complex numbers such that |2z - w| = 25, |z + 2w...