# aaahhhhh urgent help!! complex no.s

Forums Leaving Cert Maths aaahhhhh urgent help!! complex no.s

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• #871

:p+2qi=17(3-2i)

****** 1-4i

ignore the asterix does any know how 2 answer this its question 4)c)ii) on de 2006 leaving cert paper !!1 and can any1 tell me where i can get de rest of de answers worked out!! i mean de full ans not jus de end bit!!

tanx

• #14837

p+2qi=17(3-2i)

****** 1-4i

ignore the asterix does any know how 2 answer this its question 4)c)ii) on de 2006 leaving cert paper !!1 and can any1 tell me where i can get de rest of de answers worked out!! i mean de full ans not jus de end bit!!

tanx

• #14838 Anonymous

do (p+2qi)(1-4i) = 17(3-2i)

=> p + 4pi + 2qi – 8q(i)(i) = 51 – 34i……..(i)(i)=1squared=-1 because i=square root of -1(imaginary number)

=> p + 4pi + 2qi +8q = 51 – 31i

=> (p + 8q) + (4p + 2q)i = (51) – (31)i

R I R I ….R=REAL NO., I=IMAGINARY NO.

=> p + 8q = 51 ….Real no. = Real no.

=> 4p + 2q = -31 ….Imaginary no. = Imaginary no.

then just do simultanious equations to get the answer…. write it out urself 2 get a better idea,

hope it helps! Sarah

• #14839 Anonymous

Have you tried Digital Grinds?