SOLUTION: If y varies as x cubed, what must be the value of x if the value of y is to be doubled?

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Question 374269: If y varies as x cubed, what must be the value of x if the value of y is to be doubled?
Answer by Jk22(389) About Me  (Show Source):
You can put this solution on YOUR website!
If y varies as x cubed, then we have : y(x)=x^3

let double y, and find the new value of x called x' : y'(x) = 2y(x) = x'^3,

x' = (2y(x))^(1/3) = 2^(1/3)(x^3)^(1/3) = 2^(1/3)x,

hence x has to be multiplied by the 3rd-root of two, or by 2^(1/3)