Trigonometric function graphs

periodic, cyclic, repeating

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Interactive trig functions app
Interactive circle, trig, radians, arc length app
Interactive Laws of sines and cosines app

  
SOH CAH TOA:

If know distance adj to pole, tower, etc. and angle a to top of the pole,
then the height opp of the pole is adj · tan a and
the dsitance hyp to top of pole is adj · sec a

If know distances adj to pole, tower, etc. and hyp to top of pole
then the height opp of the pole is adj · tan(arccos(a/hyp))


The co- functions are the corresponding trig function of the complement of the angle:
cos(a) = sin(90-a)
cot(a) = tan(90-a)
csc(a) = sec(90-a)

sine is the fundamental function, all others can be drefined in terms of it:
cos(x) = sin(x+π/2)

   

360° / 2π radians = ~57° / 1 radian
Unit circle: center angle in radians equals arc length
Unit circle: sector of central angle 1 radian has area 1/2
Degrees ° a Radians x = cos a y = sin a x2+y2=1 slope of tangent line = - 1 / tan a = -cot a
0 0 1 0 1+0
~14.47 ~.2527 √15/4 ≈.968 1/4=.25 15/16+1/16 -√15 ≈-3.873
15 π/12 ≈ .2618 (√6+√2)/4≈.966 (√6-√2)/4≈.258 .933+.0667 -(2+√3) ≈-3.732
30 π/6 ≈ .5235 √3/2 ≈.866 1/2=.5 3/4+1/4 -√3 ≈-1.732
~35.26 ~.6155 √2/√3 ≈.816 1/√3 ≈.577 2/3+1/3 -√2 ≈-1.414
45 π/4 ≈ .7853 √2/2 ≈.707 √2/2 ≈.707 1/2+1/2 -1
~54.74 ~.9553 1/√3 ≈.577 √2/√3 ≈.816 1/3+2/3 -1/√2 ≈-.707
~57.29 1 ~.5403 ~.8414 .2919+.7079 ~-.642
60 π/3 ≈ 1.047 1/2=.5 √3/2 ≈.866 1/4+3/4 -1/√3 ≈-.577
75 5π/12 ≈ 1.309 (√6-√2)/4 ≈ .2588 (√6+√2)/4 ≈ .966 .067+.933 -(2-√3) ≈-.268
~75.52 ~1.318 1/4=.25 √15/4 ≈.968 1/16+15/16 -1/√15 ≈-.258
90 π/2 ≈ 1.571 0 1 0+1 0

change in sine every 15°
15° 30° 45° 60° 75° 90°
sine 0 .258 .5 .707 .866 .968 1
Δ .258 .244 .207 .159 .104 .032








First and second derivatives of sine function:


First and second derivatives of tan function:



     
     


   
       
   
       
           

     

     

     
     






           
  
hyperbolic sin and hyperbolic cos: