What's the derivative of y with respect to x? This is equal to, just using the power rule, four x to the third power. And so what we have to test is, is four x to the third power, that's the derivative of y with respect to x, equal to four times y. Instead of writing a y, I'm gonna write it all in terms of x. So is that equal to four times x to the fourth, because x to the fourth is the same thing as y, divided by x. And so let's see, x to the fourth divided by x, that is going to be x to the third. And so you will indeed get four x to the third is equal to four x to the third.