2x^2+4x+y=0 become y=-2x^2-4x...parabola belo x-axis
line y=2x=strate line that go up on rite side av y-axis
Assuming yu start at x=0 & want the part for x gotu a positiv number a...
add the areas: line alwaes abuv x-axis & parabola belo it
strate line make triangel so area=xmax*ymax/2 & ymax=2*xmax, so that area=xmax^2
area belo x-axis...integrate -2x^2-4x...-(2/3)x^3-2x^2 from x=0 tu x=xmax
become -(2/3)xmax^3-2xmax^2