V1 - x2 B https://www.desmos.com/calculator/2fnu9mbwte a X a) The blue shaded region A, of the unit circle is a sector with central d) The vertex of the triangle corresponding with / is B(x, h). Use the angle y. The tan shaded region A2 is a right triangle with base fact that A lies on the unit circle centered at the origin to write measuring x and acute angles o, /. The elementary geometric area formulas give h = h(x) = A e) With the above we are able to write the shaded areas as functions and A2 h. of X: b) Since B, y are [ CIRCLE ONE: vertical / alternate / corresponding ] A, = A, (x) = angles, we conclude that and B = A2 = A2(x) = c) We know that f) Write the sum of A, and A, as a single definite integral sin B = b(x) f(t) dt. so that we can write Y = Y (= A + A, =