Trig identites Flashcards
1
Q
Power reducing formula for sin^2(u)
A
2
2
Q
Power reducing formula for cos^2(u)
A
2
3
Q
Power reducing formula for tan^2(u)
A
1 - cos(2u)
—————- (form for sin / form for cos)
1 + cos(2u)
4
Q
Pythagorian identity
A
sin^2(x) + cos^2(x) = 1
5
Q
sin^2(x) can be rewritten as
A
1 - cos^2(x)
6
Q
cos^2(x) can be rewritten as
A
1 - sin^2(x)
7
Q
1/sin(x)
A
csc(x)
8
Q
1/cos(x)
A
sec(x)
9
Q
sin(u +/- v)
A
sin(u)cos(v) +/- sin(v)cos(u)
10
Q
cos(u +/- v)
A
cos(v)cos(v) -/+ sin(u)sin(v)
11
Q
can be derived by dividing pythagorean identity by cos(x)
A
1 + tan^2(x) = sec^2(x)
12
Q
can be derived by dividing pythagorean identity by sin(x)
A
1 + cot^2(x) = csc^2(x)
13
Q
cos =
A
adj/hyp or x/r
14
Q
sin =
A
opp/hyp or y/r
15
Q
ln(x^a)
A
a*ln(x)
