# Plot an equation in time span T=[0,t]

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Fatemeh Salar on 9 Jul 2022
Edited: Karim on 9 Jul 2022
Hi,
I am about to plot an equation but i have 4 variables (including t), how can I plot this equation in domain of 0-T ?
clc
clear
close all
if(a*b/c>1)
for(0:t)
y=(e^a)*sin(c*t)/sqrt(b);
plot(t,y)
end
elseif(a*b/c<1 && a*b/c>0)
y=sin(a)*sqrt(b*t)/sin(c);
plot(t,y)
elseif(a*b/c<1)
y=cos(a)*e^(b*t)/(c);
plot(t,y)
end
thanks

Karim on 9 Jul 2022
Edited: Karim on 9 Jul 2022
You need to create a vector, below you can see a method using the "linspace" function. This creates a vector between 0 and t with 100 elements.
a = 3; % input('Please enter a : ')
b = 2; % input('Please enter b : ')
c = 7; % input('Please enter c : ')
t = 5; % input('Please enter t : ')
% create a vector T between [0 T] with 100 elements
t = linspace(0,t,100);
check = a*b/c;
if check > 1
y = (e^a)*sin(c.*t)./sqrt(b);
elseif check <= 1 && check >= 0
y = sin(a)*sqrt(b.*t)./sin(c);
else % i.e. check < 1
y = cos(a)*e.^(b.*t)./c;
end
figure
plot(t,y)
xlabel('t axis')
ylabel('y values')
grid on ##### 2 CommentsShowHide 1 older comment
Fatemeh Salar on 9 Jul 2022
Yes, I've also forgot to put "." notion since its element-wise operations! Thanks

Fatemeh Salar on 9 Jul 2022
Dear @Karim
Thank you so much.