Integration is the reverse process of differentiation. Indefinite integrals do not have upper and lower bounds to evaluate and when integrating. When integrating, ∫f(x) dx will become "F(x) + C".
Simplify the expression. If it is possible, pull out any constant multiples in front of the integral. It may make the expression easier to deal with. Check for any common trigonometric substitutions such as the double-angle formulas. One of the double-angle formulas is sin(2a)=2sin(a)*cos(a). Other trigonometric substitutions can be found in the resources section.
Integrate the expression using the general power formula, parts, partial fractions or another integration method. To integrate using the general power formula, ∫x^n dx becomes (x^(n+1))/(n+1). To see more information on the other integration methods, see the resources section.
Add a "+ C" to the end of the expression you came up with in step 2. This "C" represents the constant that cannot be determined in the integration process of an indefinite integral. The result is a set of functions that varies by the "C."