Studied by 23 peoplesin^2x+cos^2x
=1
cos^2x-sin^2x
=cos2x
1+cot^2x
=csc^2x
tan^2x+1
=sec^2x
sinx
=1/cscx
cosx
=1/secx
tanx
=1/cotx
cos(-x)
=cosx
sec(-x)
=secx
tan(-x) or -tanx
=sin(-x)/cos(-x)
even
cosx, secx
odd
sinx, cscx, tanx, cotx
sin(pi/2-x)
=cosx
cos(pi/2-x)
=sinx
tan(pi/2-x)
=cotx
csc(pi/2-x)
=secx
sec(pi/2-x)
=cscx
cot(pi/2-x)
=tanx
sin(u+v)
= sin(u)cos(v) + cos(u)sin(v)
sin(u-v)
= sin(u)cos(v)-cos(u)sin(v)
cos(u+v)
= cos(u)cos(v)-sin(u)sin(v)
cos(u-v)
= cos(u)cos(v) + sin(u)sin(v)
tan(u+v)
= tan(u)+tan(v)/1-tan(u)tan(v)
tan(u-v)
= tan(u)-tan(v)/1+tan(u)tan(v)
sin2(u)
= 2sin(u)cos(u)
tan2(u)
= 2tan(u)/1-tan(u)^2
cos2(u)
cos^2(u)-sin^2(u) OR 2cos^2(u)-1 OR 1-2sin^2(u)
θ
full angle
θ/2
half angle
The + or - depends on the __ in which θ/2 lies
quadrant
sin θ/2
± √ (1 - cosθ)/2
cos θ/2
± √(1 + cos θ)/2
tan θ/2
±√(1-cosθ)/(1+cosθ)
Note
Flashcard