Touba M. answered 03/10/20
B.S. in Pure Math with 20+ Years Teaching/Tutoring Experience
hi
you need to know ∫sin-1 ax dx = x sin -1ax + 1/a √1-a^2x^2
area = ∫ sin-1 (x/4) dx = x sin-1 (x/4) + 4 √1-(x/4)2 from x = 0 to x = 4
area = 4 sin-1 (4/4) + √1-(4/4)^2 - 0 -4 √1 - 0
area = 4 (Π/2 ) + 0 - 0 - 4
area = 2Π - 4
I hope it is useful,
Minoo