clear
close all
x = linspace(0,1,21)';
for i = 1:length(x)
    Q(i) = integral(@prob3fun,0,x(i));
end
Q = Q(:);

Qtotal = Q(end);
ystar = [0.17 0.46 0.83]*Qtotal;
xstar(1) = invinterp(x,Q,ystar(1));
xstar(2) = invinterp(x,Q,ystar(2));
xstar(3) = invinterp(x,Q,ystar(3));

figure(1)
   hold on
   plot(x,Q,'r-')
   plot(x,Q,'bo')
   plot(xstar,ystar,'k*')