Chapter 23 - Trigonometric Identities in Integration Flashcards
1
Q
What is the double angle formula for sin ?
A
sin 2A = 2sinAcosA
2
Q
What is the double angle formula for cos? - show all three
A
cos2A = cos^2A - sin^2A cos2A = 2cos^2A - 1 cos2A = 1- 2sin^2A
3
Q
What is the double angle formula for tan?
A
tan 2A = 2tanA/1-tanA
4
Q
How can we use these in integration?
A
Replace original equations prior to integration.
5
Q
What other identities can we use?
A
cos^2 x + sin^2 x = 1
sec^2 x = 1 + tan^2 x
1 + cot^2 x = cosec^2 x
6
Q
When will these be especially useful?
A
When dealing with tan^2 or cot^2
