Lesson #129
Integrals involving
Trig Quadratics




Quote of the Day:

"God grant me the serenity to accept the things I cannot change, the courage to change the things I can, and the wisdom to know the difference."
-- Reinhold Niebuhr



Objectives:

The student will integrate integrals involving quadratics.

The student will complete the square.



1. Collect homework.

2. Review the concept of "Completing the Square."

To complete the square:
(1) If the coefficient of the squared term is one:
(2) Divide the linear term by 2 and square it.
(3) Add and subtract this amount to the expression.

(1) If the coefficient of the squared term is not one:
Factor out any coefficient of the squared term.
(2) Divide the linear term by 2 and square it.
(3) Inside the parentheses, add this amount.
Outside the parentheses, subtract this amount times the number which you factored out of the leading coefficient.

Examples:



Rewrite each of the following expressions in the form of a perfect square and a constant:



3. If an integral involves a quadratic, you can complete the square to get an integral that contains the sum or difference of two squares. Then use the method of trig substitution.

4. Examples:





5. Assignment:
p. 535 (33, 34, 37, 38)

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Send any comments or questions to: David Pleacher