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# Parametric equations watch

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

simplify

do the same for 3x-4y
3. (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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Updated: February 2, 2005
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