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3 Variables Simultaneous Equations HELP! (1 Viewer)

bored.of.u

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im having difficulty with this question:

Find real numbers p, q and r such that:

p^2 + q^2 + r^2 = 1
p + q + r = 3
p + 2q - r = 5

Thanx in advance =D
 

Timothy.Siu

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im having difficulty with this question:

Find real numbers p, q and r such that:

p^2 + q^2 + r^2 = 1
p + q + r = 3
p + 2q - r = 5

Thanx in advance =D
question seems dodgey,
from the first equation it is obvious that p,q,r<1
but p+q+r=3?
or am i doing something wrong
 

Templar

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im having difficulty with this question:

Find real numbers p, q and r such that:

p^2 + q^2 + r^2 = 1
p + q + r = 3
p + 2q - r = 5

Thanx in advance =D
From (3), we have r=p+2q-5
Sub into (2), p+q+p+2q-5=3
or 2p+3q=8, so p=(8-3q)/2
Sub into (1) and using r=(q-2)/2

(8-3q)^2+4q^2+(q-2)^2=4

Expand and solve (as pointed out above, quadratic has no real solutions)
 
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bored.of.u

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From (3), we have r=p+2q-5
Sub into (2), p+q+p+2q-5=3
or 2p+3q=8, so p=(8-3q)/2
Sub into (1) and using r=(q-2)/2

(8-3q)^2+4q^2+(q-2)^2=4

Expand and solve (as pointed out above, quadratic has no real solutions)
thanx templar =D
 
Last edited:

h3ll h0und

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LOL u cheapo bored.of.u
i shudv seen this thread b4 and i wudv got that mark .... :(
i thought u had to do the hw under exam condition xD hahaha naa jokes i did the same for physics lol
 

bored.of.u

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LOL u cheapo bored.of.u
i shudv seen this thread b4 and i wudv got that mark .... :(
i thought u had to do the hw under exam condition xD hahaha naa jokes i did the same for physics lol
lol im azn what did u expect...nah the question states find the real values but i proved the question wrong so i was checking on BoS.
 

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