I want to calculate the following integral with Matlab:
integral x*sin(3x)*e^(x^3) dx from bound 1 to 5.
Use following commands, but not answer my integral.
syms x
f=x*sin(3*x)*exp(x^3);
int (x*sin(3*x)*exp(x^3),x,1,5)
where part of my code is wrong? anyone can help me?
Your procedure is correct. The problem is that Matlab doesn't know an explicit form for the primitive function. It produces the warning
Warning: Explicit integral could not be found
If you change x^3 to x, for example, there is an explicit integral (which can probably be found integrating by parts, as usual with products of exponential and trigonometric functions):
>> syms x
>> int(x*sin(3*x)*exp(x),x,1,5)
ans =
(exp(1)*(12*cos(3) - 9*sin(3)))/50 - (exp(5)*(72*cos(15) - 29*sin(15)))/50