inverse to a sin...

[Devin]

is there an inverse to a sin? What I mean by that is... is there a function that goes the other way?

ie:

(* (sin angle_from_xy_plane) distance) = 3dpoint projected up distance

How do you go the other way and project a point from the xy plane to 3d space?

Thanks,

Devin

 

[Phil Clark]

(defun ACOS (X) ;Inverse cosine
(- (/ pi 2.0) (atan (/ X (sqrt (- 1.0 (* X X))))))
)
(defun ASIN (X) ; Inverse sine
(atan (/ X (sqrt (- 1.0 (* X X)))))
)
(defun ACSC (X) ; Inverse cosecant
(+ (atan (/ 1.0 (sqrt (- (* X X) 1.0)))) (* (/ pi 2.0)
(- (if (< X 0) (- 1.0) (+ 1.0)) 1.0)))
)
(defun ASEC (X) ; Inverse secant
(+ (atan (sqrt (- (* X X) 1.0))) (* (/ pi 2.0)
(- (if (< X 0) (- 1.0) (+ 1.0)) 1.0)))
)
(defun ACOT (X) ; Inverse cotangent
(- (/ pi 2.0) (atan X))
)
(defun SEC (X) ; Secant
(/ 1.0 (cos X))
)
(defun CSC (X) ; Cosecant
(/ 1.0 (sin X))
)
(defun TAN (X) ; Tangent
(/ (sin X) (cos X))
)
(defun COT (X) ; Cotangent
(/ (cos X) (sin X))
)

 

[Devin]

Thanks Phil

Devin