Find $f_{xx},f_{xy},f_{yx}$, and $f_{yy}$ for the following function. (Remember, $f_{yx}$ means to differentiate with respect to $y$ and then with respect to $x$.)
$$f(x,y)=2x+3y$$

Step 1 ：The function given is $f(x,y)=2x+3y$.

Step 2 ：First, we find the first order partial derivatives, $f_x$ and $f_y$, which are the derivatives of the function with respect to $x$ and $y$ respectively.

Step 3 ：The derivative of $f$ with respect to $x$ is $f_x=2$.

Step 4 ：The derivative of $f$ with respect to $y$ is $f_y=3$.

Step 5 ：Next, we find the second order partial derivatives, $f_{xx}$, $f_{xy}$, $f_{yx}$, and $f_{yy}$. These are the derivatives of the first order partial derivatives.

Step 6 ：To find $f_{xx}$, we differentiate $f_x$ with respect to $x$, which gives $f_{xx}=0$.

Step 7 ：To find $f_{xy}$, we differentiate $f_x$ with respect to $y$, which gives $f_{xy}=0$.

Step 8 ：To find $f_{yx}$, we differentiate $f_y$ with respect to $x$, which gives $f_{yx}=0$.

Step 9 ：To find $f_{yy}$, we differentiate $f_y$ with respect to $y$, which gives $f_{yy}=0$.

Step 10 ：Final Answer: The second order partial derivatives of the function $f(x,y)=2x+3y$ are $\boxed{{\displaystyle f_{xx}=0,f_{xy}=0,f_{yx}=0,f_{yy}=0}}$.