How can I increase the equation size in an array for better alignment?

[Dustinsfl]

I had to use an array to center and left align two different equations--a system of DEs.

However, by using array, the equations are smaller than I would like.

How can I increase the the equation size in the array.

$$\displaystyle\begin{array}{lcl}
\frac{dN_1}{dt} & = & r_1N_1\left(1 - \frac{N_1}{K_1} - b_{12}\frac{N_2}{K_1}\right)\\
\frac{dN_2}{dt} & = & r_2N_2\left(1 - b_{21}\frac{N_1}{K_2}\right)
\end{array}$$

On MHB, the equations are a nice size in the array but on a LaTex document they aren't.

I would like my document equations to be the size of the MHB equations in the array.

 

[masters1]

I had to use an array to center and left align two different equations--a system of DEs.

However, by using array, the equations are smaller than I would like.

How can I increase the the equation size in the array.

$$\displaystyle\begin{array}{lcl}
\frac{dN_1}{dt} & = & r_1N_1\left(1 - \frac{N_1}{K_1} - b_{12}\frac{N_2}{K_1}\right)\\
\frac{dN_2}{dt} & = & r_2N_2\left(1 - b_{21}\frac{N_1}{K_2}\right)
\end{array}$$

On MHB, the equations are a nice size in the array but on a LaTex document they aren't.

I would like my document equations to be the size of the MHB equations in the array.

Maybe put \huge in front of it..$$\huge \displaystyle\begin{array}{lcl} \frac{dN_1}{dt} & = & r_1N_1\left(1 - \frac{N_1}{K_1} - b_{12}\frac{N_2}{K_1}\right)\\ \frac{dN_2}{dt} & = & r_2N_2\left(1 - b_{21}\frac{N_1}{K_2}\right) \end{array}$$

 

[Dustinsfl]

Huge is bit too big. Are there any other qualifiers?

I found \large which worked nicely.

 

[Ackbach]

I had to use an array to center and left align two different equations--a system of DEs.

However, by using array, the equations are smaller than I would like.

How can I increase the the equation size in the array.

$$\displaystyle\begin{array}{lcl}
\frac{dN_1}{dt} & = & r_1N_1\left(1 - \frac{N_1}{K_1} - b_{12}\frac{N_2}{K_1}\right)\\
\frac{dN_2}{dt} & = & r_2N_2\left(1 - b_{21}\frac{N_1}{K_2}\right)
\end{array}$$

Try instead

\begin{align*}
\frac{dN_1}{dt} & = r_1N_1\left(1 - \frac{N_1}{K_1} - b_{12}\frac{N_2}{K_1}\right)\\
\frac{dN_2}{dt} & = r_2N_2\left(1 - b_{21}\frac{N_1}{K_2}\right).
\end{align*}

The array environment can be used for multi-line equations, but I find the align environment to be much better. You may need to have a usepackage command in there to make it work.

 

[rapid1]

\usepackage{amsmath} for the \begin{align} environment.