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how do i do this

i missed my first further maths lesson and he has set some hwk but i am really confused....i would really appreciate some help. the question is:

Find the values of p and q given that p+qi=1/12-5i
Reply 1
Avatar for j1i9s9s5
j1i9s9s5
7
Original post by NooNoo1
i missed my first further maths lesson and he has set some hwk but i am really confused....i would really appreciate some help. the question is:

Find the values of p and q given that p+qi=1/12-5i


Equating real and imaginary parts of this equation will yield p and q. However the RHS is not immediately in a form that you can say this is the real part and this is the imaginary part. How can you re write the RHS so it is in the form a +bi (for some a and b)? HINT: Think about the conjugate of a complex number.
Reply 2
Avatar for Krollo
Krollo
17
You could also think about it as rationalising the denoninator.

Posted from TSR Mobile
Reply 3
Avatar for j1i9s9s5
j1i9s9s5
7
Original post by Krollo
You could also think about it as rationalising the denoninator.

Posted from TSR Mobile


No, You are 'making' the denominator real not rationalising.
Reply 4
Avatar for Krollo
Krollo
17
Original post by j1i9s9s5
No, You are 'making' the denominator real not rationalising.


I said it could be thought of as rationalising as the processes are fairly similar. I never said it was rationalising.

Admittedly it's never a good idea to use wrong terminology, but you get where I'm coming from.
Original post by Krollo
I said it could be thought of as rationalising as the processes are fairly similar. I never said it was rationalising.

Admittedly it's never a good idea to use wrong terminology, but you get where I'm coming from.


Technically you are 'realising' the denominator.
Multiply the 1/(12-5i) by (12+5i)/(12+5i)

This gives (12+5i)/(144+25) = 12/169 + 5/169 i

so p=12/169 , q=5/169
Reply 7
Avatar for j1i9s9s5
j1i9s9s5
7
Original post by Some Math Nerd
Multiply the 1/(12-5i) by (12+5i)/(12+5i)

This gives (12+5i)/(144+25) = 12/169 + 5/169 i

so p=12/169 , q=5/169


Please don't give them the answer straight away. You're supposed to try and help; not do it.

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