## iop360 Group Title solve for z, and give your answer in the form a + bi (conj)z+2z = 2+4i+conj(7+3i) **conj refers to conjugate of a complex number (a line on top of it) one year ago one year ago

1. iop360 Group Title

answer is 3+i (need to learn how to do it)

2. math>philosophy Group Title

I don't understand the notation of the equation. Why did you put (conj)? Does it mean take the conjugate of the term that follows it? Or multiply that term by its conjugate? Or what?

3. iop360 Group Title

i dont know how to write a line above the letter for this

4. iop360 Group Title

so for this question, there would be a line above the z and the 7+3i

5. iop360 Group Title

z = a + bi (conj)z = a - bi

6. iop360 Group Title

it means to flip the sign of the imaginary part

7. math>philosophy Group Title

So why don't you just write z - 2z = 2 + 4i + (7 - 3i)? Is that what the question says?

8. iop360 Group Title

no, there is no line above the z+2z, just the z

9. math>philosophy Group Title

Can you draw the question instead?

10. iop360 Group Title

|dw:1353720314063:dw|

11. tkhunny Group Title

$$\bar{z} + 2z = 2 + 4i + \overline{7+3i} = 2 + 4i + 7 - 3i = 9 + i$$

12. iop360 Group Title

answer is 3+i though...you seem to be on the right track though

13. math>philosophy Group Title

no idea what the conjugate of a variable means...

14. math>philosophy Group Title

unless you use fourier which i don't think you are

15. tkhunny Group Title

It's not my problem statement. You need to be on the right track. Where shall we go from here? $$\bar{z} + 2z = 9 + i$$

16. iop360 Group Title

i dont know what the z part is. that is the problem

17. iop360 Group Title

is z considered real or imaginary?

18. iop360 Group Title

i tried it with both for hours

19. tkhunny Group Title

Please read the problem statement. "solve for z, and give your answer in the form a + bi" z is a Complex Number

20. math>philosophy Group Title

oh

21. tkhunny Group Title

You tried what? $$\bar{z} + 2z = a - bi + 2(a + bi) = a - bi + 2a + 2bi = (a + 2a) + (2b-b)i$$ Do yuo see where this is going?

22. iop360 Group Title

no

23. iop360 Group Title

i understand why you get this but why did you do this

24. iop360 Group Title

you equate this to 9+i?

25. tkhunny Group Title

That is it! $$3a + bi = 9 + i$$

26. iop360 Group Title

thanks