MATLAB: Integrating sin(2x) in MATLAB

integration

Introduction:

I'm new to MATLAB and trying to learn how to integrate expressions.

Situation:

The expression to integrate is…..

sin(2x)

I'm entering the following code……

syms x

int(sin(2*x))

The answer MATLAB is displaying is…..

ans =

sin(x)^2

The answer I'm looking for is……. (-1/2)*cos(2x)+c

Best Answer

syms x
out = feval(symengine,'combine',int(sin(2*x)),'sincos')

Related Solutions

MATLAB: How to solve this integration ???

This shows that MATLAB is not able to find a closed-form expression for the integration problem. You can still find the numerical answer by substituting the numeric values of a and b

syms x a b
c = (x*cos(x)*sin(x))/(a^2*cos(x)^2 + b^2*sin(x)^2)^2;
c_int = int(c, x, 0, pi/1);
x = subs(c_int, [a b], [1 2]);

This will give the value of integration at a=1, b=2. Result:

>> x
x =
-pi/12

MATLAB: Problem Integrating sin(2*x)

The integral is:

sin(x)^2 + C

but Matlab just doesn't show the constant. How do you get the -1/2? Because if you differentiate the integral (sin(x)^2 + C) you get:

2*sin(x)*cos(x) = sin(2*x)

And the constant differentiated gives 0 since it doesnt depend on x.

Best Answer

Related Solutions

MATLAB: How to solve this integration ???

MATLAB: Problem Integrating sin(2*x)

Related Question