• → Cancel

Apart

WMA link

Apart[expr]

writes expr as a sum of individual fractions.

Apart[expr, var]

treats var as the main variable.

• • Apart[1 / (x^2 + 5x + 6)]

When several variables are involved, the results can be different
depending on the main variable:

• • Apart[1 / (x^2 - y^2), x]

• • Apart[1 / (x^2 - y^2), y]

Apart is Listable:

• • Apart[{1 / (x^2 + 5x + 6)}]

But it does not touch other expressions:

• • Sin[1 / (x ^ 2 - y ^ 2)] // Apart