Define equation
In previous releases, eq
in some cases
evaluated equations involving only symbolic numbers and returned logical 1
or 0
.
To obtain the same results as in previous releases, wrap equations
in isAlways
. For example, use isAlways(A
== B)
.
A == B
eq(A,B)
creates
a symbolic equation. You can use that equation as an argument for
such functions as A
== B
solve
, assume
, ezplot
,
and subs
.

Number (integer, rational, floatingpoint, complex, or symbolic), symbolic variable or expression, or array of numbers, symbolic variables or expressions. 

Number (integer, rational, floatingpoint, complex, or symbolic), symbolic variable or expression, or array of numbers, symbolic variables or expressions. 
Solve this trigonometric equation. Define the equation by using
the relational operator ==
.
syms x solve(sin(x) == cos(x), x)
ans = pi/4
Plot the equation
. Define the equation by using the ==
operator.
syms x y fimplicit(sin(x^2) == sin(y^2))
Test the equality of two symbolic expressions by using isAlways
.
syms x isAlways(x + 1 == x + 1)
ans = logical 1
isAlways(sin(x)/cos(x) == tan(x))
ans = logical 1
Check the equality of two symbolic matrices.
A = sym(hilb(3)); B = sym([1, 1/2, 5; 1/2, 2, 1/4; 1/3, 1/8, 1/5]); isAlways(A == B)
ans = 3×3 logical array 1 1 0 1 0 1 1 0 1
If you compare a matrix and a scalar, then ==
expands
the scalar into a matrix of the same dimensions as the input matrix.
A = sym(hilb(3)); B = sym(1/2); isAlways(A == B)
ans = 3×3 logical array 0 1 0 1 0 0 0 0 0