error in plot command while using for loops twicly

I am trying to plot as?

function output=fun(Q,T,x)

output=2.*Q.*T.*x

end

function f=fun2(Q,T,x)

T=[2 5]

Q=linspace(0,0.8)

for i=1:length(T)

for j=1:length(Q)

f=fun(Q(j),T(i),x)

end

end

end

%% then to run it in Main_drag2.m file as

A=fun2(Q,T,x)

plot(Q,A(1,:))

%%but i got the error as below

%%Error using plot

%%A numeric or double convertible argument is expected

%%Error in Main_drag2 (line 23)

%%plot(Q,A(1,:))