Linearity

sums of integral is integrals of sums

Apply fundamental theory of calculus:

same as

applying fundamental theorem:

always

, no matter it’s written as , , or

abbreviation of integrals

substituting variable

Composition of functions

differentiate w.r.t. or :

or simply:

By applying Fundamental Theorem of Calculus:

multiplying

Or simply:

by using Fundamental Theorem of Calculus:

for example: