Inactivate an expression:

Activate it:

Inactivate an expression with several terms:

Activate different parts of the expression:

Inactivate a symbol in an expression:

Evaluate the expression:

Inactivate an expression:

Evaluate the expression:

Inactivate the symbol g only:

Activate g:

Inactivate g and h:

Activate h only:

Inactivate all symbols except Integrate in an expression:

Evaluate the expression:

Prevent numeric functions from being inactivated:

Normally Plus and Sin would also have been inactivated:

Define a trigonometric expression:

Activate different trigonometric functions:

Define , leaving both the derivative and integral inactive:

Differentiate the integral without evaluating the integral:

Activate the integral to compute the final result:

Integrate without performing the differentiation:

Activate the differentiation to compute the final result:

The results are mathematically the same:

Show identities including Leibniz's rule for differentiating integrals:

Chain rule:

Indefinite integrals:

Infinite sums and products:

Activate is the inverse of Inactivate :

Inactivate replaces specific symbols with their inactive forms:

Activate replaces all instances of inactive symbols with their active forms:

Inactivate maintains symbols in inactive form and allows parts of expressions to be inactive:

Hold maintains expressions in unevaluated form, and all parts are inactive:

Compare an inactive expression with the corresponding FullForm :

Inactivate is an idempotent operator:

Certain heads are not inactivated by default, including List , Rule () and Blank (_):

Using Replace at all levels can inactivate all heads in an expression:

As compound heads have no attributes, the use of Inactivate can lead to evaluation leaks:

Normally, the HoldAll attribute of Sum would prevent the k from evaluating:

Create a gallery of definite integrals: