Trigonometry.

Trigonometry.

1. General recap identities

   • Sinx/cosx = tanx
   • sin^2x + cos^2x = 1
     • 1+ cot^2x = cosec^2x
     • tan^2x+ 1 = sec^2x

2. Graphs

   • sinx
     • Period of 360 degrees. Max: 1 Min: -1. Hidden value= 180-ANS then add 360.
   • cosx
     • Period of 360 degrees Max: 1 Min: -1. Hidden value= -ANS then add 360.
   • tanx
     • Period of 180 degrees. No max or min. Hidden values +/- 180.
   • cosecx= 1/sinx
   • secx= 1/cosx
   • cotx= 1/tanx
     • = cosx/sinx

3. Compound Angle Formula

   • Sin(A+/-B) = sinAcosB +/- cosAsinB
   • Cos(A+/-B) = cosAcosB -/+ sinAsinB
   • Tan(A+/-B) = tanA +/- tanB / 1 -/+ tanAtanB

4. Double Angle Formula

   • Sin2A = sin(A+A) = 2sinAcosA
   • Cos2A = cos(A+A) = 1-2sin^2A or 2cos^2A-1
   • Tan2A = tan(A+A) = 2tanA / 1-tan^2A

5. asinx+bcosx

   • Rcos(A+B)= R(cosAcosB-sinAsinB)
   • Rcos(A-B)= R(cosAcosB+sinAsinB)
   • Rsin(A-B)= sinAcosB-cosAsinB
   • Rsin(A+B)= sinAcosB+cosAsinB