How can I calculate the area of this curve?

As you can see, there are two curves. First one is R=1, and the other one is y=cos(x). How can I find the area marked with hachure?

Answer 1

[Joseph Lee]

I assume you have the equation for the semicircle as well,

1. Find the intersection points between the two curves, x1 & x2( the two black lines)
2.Find blue area under the cos(x) curve using integration from x1 to x2
3.Find red area under the semi-circle using integration from (x2-1) to x1
4. Add blue and red area = answer

[Arthur II]

so this is my way:

with this calculation I found (x1), and x2 is 1.5 then the area:

int y= radikal ( (r^2 - (x+a)^2) x , x1 )
+
int (cos(x), x1, x2)

if that's right, could you please help me to convert these rule to matlab language? actually I'm little bit confused how I can.