function Apr15()
% Note that (a*exp(b*t(1))-y(1))^2 + ... + (a*exp(b*t(m))-y(m)^2 =
%               norm(y - exp(b*t)*a)^2.
% If b is fixed then from normal equations 
%    a_opt = y'*exp(b*t)/(exp(b*t)'*exp(b*t))
%
% so hand this function over to fminbnd...

function z = Myf(b,t,y)
a_opt = y'*exp(b*t)/(exp(b*t)'*exp(b*t)) 
z = norm(y - exp(b*t)*a_opt)^2

