plot function in a specific interval while the other interval function is equal to zero

how can i plot the following fucntion

g(t)= t^2+ 2*t+3 , 5 < t < 20

g(t)= 0 , t < 5 & t > 20

Answer 1

[madhan ravi]

See if this helps to understand how to solve your homework:

    t=1:.1:10;
    g=t.^2.*(t>=1 & t<5) + t.*(t>=5 & t<=10);
    plot(t,g)

[madhan ravi]

Hint: One of your time interval should use "|" instead of "&".

[Mohamed karam]

thankyou madhan for your response.

actually i tried your code but no change. your code gives the same results as no constraints.

[madhan ravi]

Show what you have tried.

[Mohamed karam]

i appreciate if you could help

i need y(t) equal to zero when no input exists

this is my code:

clc; clear all; close all

syms y(t) a b

eqn = diff(y,t,2) == 0.5*(1-diff(y,t,1)-2*y); % 2y''+y'+2y=g(t)

Dy = diff(y,t);

cond = [y(0)==0, Dy(0)==0];

y(t) = dsolve(eqn,cond)

t=0:pi/100:15*pi;

subplot(2,1,1)

t1=[0 1 2 3 4 5 5 6 7 8 9 10 11 12 13 14 15 16 17 19 20 20 21 22];

g1=[0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0 0 0];

plot (t1,g1)

grid on

xlabel('time')

ylabel('g(t)')

title('Input')

subplot(2,1,2)

plot (t,y(t))

grid on

xlabel('time')

ylabel('y(t)')

title('ODE system Response')

[Mohamed karam]

thanks a lot

I found the syntax called fplot