Yeah you can. If you draw a sketch, you should be able to identify the relevant rectangle and relevant "red area" to subtract from the rectangle area. The "red area" will be able to be computed similarly to above (integrating a function of y between y limits).Would the same principle apply for another question like "find the area btwn y=sin^-1 x/2, x=1 and x=2 and the x-axis?