9. Direct Variation
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What is the form of a direct variation equation?
y=392
Functions where y varies directly with x^2 — direct variation equations — follow a specific format.
y= kx^2
In this form, k≠0.
By substituting the given values for x and y into the equation, we can determine the constant of variation, k.
x= 6, y= 72
Calculate power
Rearrange equation
.LHS /36.=.RHS /36.
Calculate quotient
Now that we have the constant of variation, we can write the function. y= 2x^2 With this equation, we can find any value of x or y when we are given the other. In this case, we are looking for y when x=14.
For the equation y=2x^2, when x=14, the value of y is 392.