I would add one variable inside function

I have x(t) and I would to create x(t+ta) by matlab code. For example

if I have x(t)= 2t+3 , I need to create x(t+ta)= 2t+2ta+3 and so on.

Please consider x(t)=5sin(2t+theta), and x(t+ta)=5sin(2t+2ta+theta) for your explaintion.

Thank you in advance.

Answer 1

[madhan ravi]

Read about subs() :

syms a t theta
x(t)=5*sin(2*t+theta);
subs(x(t)*x(t+a),{t,a,theta},{1,2,3}) % t with value one ,a with 2 and theta 3 are example values 

[Willim]

the answer still str , I need it as numbers to plot

[madhan ravi]

? What are the values of t , a & theta?

[Willim]

I will intgrate the x(t)*x(t+ta)

so

int(x(t)*x(t+ta),t,0,pi)/pi

the answer will be

25*cos(ta)^2 - 25/2

I would substite ta by the array [1:1:10]

I have done this but the answer is not number , I tried str2num but does not help

[madhan ravi]

double(subs(answer,ta,1:10))

[Willim]

I think double(a) works to solve this problem

Answer 2

[KALYAN ACHARJYA]

syms t ta theta
x(t)=5*sin(2*t+theta);
disp(x(t+ta))

Command Window

5*sin(2*t + 2*ta + theta)

[Willim]

Thank you but the result on disp cannot use to multiply with x(t). it gives

x(t)*disp(x(t+ta))
Error using sym/disp
Too many output arguments.
 

I need to have the result x(t)*x(t+ta).

after finding the x(t)*x(t+ta) which should be

25*sin(2*t + theta)*sin(2*t + 2*ta + theta)

How can I substitute t , theta , and ta values in

25*sin(2*t + theta)*sin(2*t + 2*ta + theta)

[KALYAN ACHARJYA]

Hello Faraj, you are doing wrong way, do the operation inside disp() only

Its giving the answer:

syms t ta theta
x(t)=5*sin(2*t+theta);
disp(x(t)*x(t+ta))