Calculator test

[Albert Chan]

(Today 03:21 PM)Commie Wrote:  Can someone please tell me how calculators calculate:

sin(2000.x)? and cos(2000.x)?

Try them in your calculator and then take the inverse to get back to 2000x? what happened to all the 2.pi circles?

2000/pi ≈ 636.619772 = 637 - 0.380228

We divide radians by pi, not (2*pi), so that reduced angle is within ±pi/2

sin(pi - x) = sin(x)

asin(sin(2000)) ≈ asin(sin(0.380228*pi)) ≈ asin(0.930040) ≈ 1.19452

637*pi - 1.19452 ≈ 2000.00000

cos(pi - x) = -cos(x)

acos(cos(2000)) ≈ acos(-cos(0.380228*pi)) ≈ acos(-0.367458) = pi - acos(0.367458) ≈ 1.94707

637*pi - (pi - 1.94707) = 637*pi - 1.19452 ≈ 2000.00000