Taylor reflection for 25 April 2010

Trig Identities

recriprocal relationships:
csc=1/ sin(theta)
sec=1/cos(theta)
cot=1/tan(theta)

relationships with negatives:
sin-theta= -sin(theta)
cos-theta= -cos(theta)
tan-theta= -tan(theta)
csc-theta= -csc(theta)
sec-theta= -sec(theta)
cot-theta= -cot(theta)

pythogorean relationships:
sin^2(theta)+cos^2(theta)=1
1+tan^2(theta)= sec^2(theta)
1+cot^2(theta)= csc^2(theta)

cofunction relationships:
sin(theta)= cos (90degrees-theta)
cos(theta)= sin (90degrees-theta)
tan(theta)= cot (90degrees-theta)
cot(theta)= tan (90degrees-theta)
sec(theta)= csc (90degrees-theta)
csc(theta)= sec (90degrees-theta)



***i need someone to give me tricks asto when to use each set of relationships to solve an equation
i.e. i need someone to help me recognize when each set of trig identities is necessary to be used