## anonymous one year ago Which of the following expressions is the conjugate of a complex number with 2 as the real part and 3i as the imaginary part? @primeralph

1. anonymous

anyone ?

2. IrishBoy123

for the conjugate of : $$z = 2 + 3i$$ if $$z = a + i \ b$$, then its conjugate $$\bar z$$ or $$z^* = a - i \ b$$

3. anonymous

how do i set it up ?

4. IrishBoy123

you have $$z=2+3i \\\ = a+i b$$ you now want $$\bar z$$ or $$z^* = a-i b$$

5. IrishBoy123

so a = and b = and thus you have the conjugate

6. anonymous

im thinking its 3i + 2. am i right

7. IrishBoy123

go back a step if $$z=2+3i =a+i \ b$$, what is a and what is b ... ?

8. IrishBoy123

which is $$z^∗=a−i \ b$$

9. anonymous

oh so 2+3i?

10. IrishBoy123

that's the number you started with you are looking for its conjugate

11. anonymous

totally confused

12. IrishBoy123

you started with $$z=2+3i$$ you want its conjugate you get there by simply reversing the sign of the imaginary part

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