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Jorge
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Please help:

If the parametric equations are:

x = 4(t + 1/t) , y= 3(t-1/t)

find and simplify expressions for 3x + 4y and 3x - 4y

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I'm afraid I can't understand what the questions asks and what I am supposed to do.

help...

jorge
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elpaw
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3x + 4y = 3 [4(t+1/t)] + 4 [3(t-1/t)]

simplify

do the same for 3x-4y
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username9816
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(Original post by Jorge)
x = 4(t + 1/t) , y= 3(t-1/t)
find and simplify expressions for 3x + 4y and 3x - 4y
1.) 3x + 4y = 3[4(t + 1/t) + 4[3(t - 1/t)] = 12(t + 1/t) + 12(t - 1/t) = 12[(t + 1/t) + (t - 1/t)] = 12(2t) = 24t

2.) 3x - 4y = 3[4(t + 1/t) - 4[3(t - 1/t)] = 12(t + 1/t) - 12(t - 1/t) = 12[(t + 1/t) - (t - 1/t)] = 12(2/t) = 24/t

Nima
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