That is, the number of intersections between the images of f(x) and sinx.
And f(x) is the odd function over the whole ring r, f(0)=0 and x >;; When 0, f (x) = (1/2) x has two intersections.
Then when f (x) =-2 x has two intersections, x < 0.
So * * * has five intersections.
That is, the number of zeros of the function F(x)=f(x)-sinx in the interval-π to π is 5.