The circle is $$x^2 + y^2 = 1,$$and the following functions are given: $$y = -1,\quad y= -x$$as shown in the image below. I need to calculate the crossing surface area of the functions (highlighted part in the image) when $x < 0.$
I have the following equation for solving the problem but I'm not sure if it's correct for this case or not: $$S(G) = ∫_a^b(f_2(x)-f_1(x))dx.$$ Can you help with it?
