matlab quad积分问题

matlab quad积分问题function y=JF(x,Ua,a,b)y=Ua*a/(pi*(a^2+(b-x)^2));end 执行quad(@(x)JF(x,75,50,200),0,400);后报错：? Error using ==> mpowerMatrix must be square.Error in ==> JF at 2y=Ua*a/(pi*(a^2+(b-x)^2));Error in ==> @(x)JF(x,75,50,200)Error in ==> quad at 77y = f(x, varargin{:});求高手指点