function Apr5()
% The graph looks like a big W 
% On [a,b] and [c,d] p''(x)>=0 and in each interval we have a local min.
% So if a<=L<R<=b  and p'(L)*p'(R)<0 then we are cool
% or if c<=L<R<=d  and p'(L)*p'(R)<0 then we are cool