R is the region below the curve y=x and above the x-axis from x=0 to x=b; where b is a positive constant.

S is the region below the curve y=cos (x) and above the x-axis from x=0 to x=b. for what value of b is R equal in area to the area of S?

so I know this means

So do I solve ?

If so I ge t 1.402