SOLUTION: If y varies directly as x^2, and if y=36 when x=2, find y when x=10.

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Question 73149: If y varies directly as x^2, and if y=36 when x=2, find y when x=10.
Answer by psbhowmick(878) About Me  (Show Source):
You can put this solution on YOUR website!
If y varies directly as x%5E2, then
y+=+kx%5E2______(1) where k = constant of variation.
When y = 36 then x=2.
So substitute these values for x & y in in equation (1)
36+=+k%2A2%5E2
36+=+k%2A4
k=36%2F4=9
So, equation (1) becomes y+=+9x%5E2
Hence when x = 10, y+=+9x%5E2+=+9%2A10%5E2+=+900.

So, when x = 10, y = 900.