Question 155653
write an equation that expresses the relationship. Use k as the constant of variation.
d varies directly as the square of y 
a) d= k sqrt y 
b) d= k/sqrt y 
c) d= ky^2 
d) d= k/ y^2
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It's c)  d = ky^2
That's the only one that is a function of y^2.  d  has y^2, but in the denominator it is y^(-2), so that's eliminated, or that would be called "varies inversely as the square of y"