Did you just change around all the x's and y's? You must actually look at the geometry.
I've been given the double integral and instructed to change the order of integration and solve. After solving the given integrals I found they equaled 1.
I reasoned that the initial graph is bounded by two lines y=x and y=3x and bounded on the x-axis between x=0 and x=1; this formed a skewed sort of triangle.
Here's what I changed it to:
I either I'm I'm messing up or my professor's solution is wrong...help?