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# Maths Problem

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1. This is an AS further maths problem for complex numbers. Can anybody please show the working for it?

Find the real numbers a and b with a>0 such that (a+bj)^2 = 1.875j

I have the solutions for a and b. It's just that my answers don't match them.
2. Is a and b sqroot15/4 ? sorry i dont latex
3. (Original post by Rose24)
This is an AS further maths problem for complex numbers. Can anybody please show the working for it?

Find the real numbers a and b with a>0 such that (a+bj)^2 = 1.875j

I have the solutions for a and b. It's just that my answers don't match them.
4. Rewrite the equation in the form (a+bj)(a+bj) = 1.875j. When you expand this out look for similarities between the LHS and the RHS
5. (Original post by Cryptokyo)
My solution in spoiler:
Spoiler:
Show

since a>0, b>0, so a=b

Please don't post full solutions - they're against the rules of this forum.

6. (Original post by Rose24)
This is an AS further maths problem for complex numbers. Can anybody please show the working for it?

Find the real numbers a and b with a>0 such that (a+bj)^2 = 1.875j

I have the solutions for a and b. It's just that my answers don't match them.
Expand and compare coefficients of j between both sides.
7. Thank you all for the help. Sorry, I posted the question incorrectly in a hurry. It was actually

(a+bj)^2 = 1-1.875j and the answers are 5/4 and -3/4

But I was doing it wrong due to a silly mistake so its ok now

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