\eqalign - Tex Command

NAME

\eqalign - Used for equation alignment; for aligning multi-line displays at a single place.

SYNOPSIS

{ \eqalign{ <math> & <math> \cr <repeat as needed> } }

DESCRIPTION

\eqalign command is used for equation alignment; for aligning multi-line displays at a single place. The ampersand is placed where alignment is desired; a double-backslash can be used in place of the \cr ; the final \\ or \cr is optional; supports only a single \tag, which is vertically centered.

EXAMPLE

1. \eqalign{
   3x - 4y &= 5\cr
   x  +  7 &= -2y
   }
   

   $ \eqalign{ 3x - 4y &= 5\cr x + 7 &= -2y } $

2. \eqalign{
   (a+b)^2 &= (a+b)(a+b) \\
           &= a^2 + ab + ba + b^2 \\
           &= a^2 + 2ab + b^2
   }
   

   $ \eqalign{ (a+b)^2 &= (a+b)(a+b) \\ &= a^2 + ab + ba + b^2 \\ &= a^2 + 2ab + b^2 } $

3. \left\{
   \eqalign{
   a &= 1\\
   b &= 2\\
   c &= 3
   }\right\}
   \qquad
   \eqalign{
   ax + by &= c \\
    x + 2y &= 3
    }
   

   $ \left\{ \eqalign{ a &= 1\\ b &= 2\\ c &= 3 }\right\} \qquad \eqalign{ ax + by &= c \\ x + 2y &= 3 } $