why there is only one value at my plot

syms t
t = 0:0.1:15;
a = ((30-30.*exp(-2.*t)).*(30.*t+15.*exp(-2.*t)+35))/(sqrt(490000-(30.*t+15.*exp(-2.*t)+35).^2));
plot(t,a)

here is my code. it just calculate a for t=15 and just show it on plot. i am new in matlab. could you help me?

Answer 1

[Tommy]

Without the below period, MATLAB is performing right matrix division on two 1x151 vectors, resulting in a scalar value.

t = 0:0.1:15;
a = ((30-30.*exp(-2.*t)).*(30.*t+15.*exp(-2.*t)+35))./(sqrt(490000-(30.*t+15.*exp(-2.*t)+35).^2));
%                                                   ^ period added here
plot(t,a)

[Hakan Güngör]

Thank you so much!!! it works now :3

[darova]