;; | ----------------------------------------------------------------------------
;; | Trignormetric functions
;; | MI_acos , MI_asin
;; | ----------------------------------------------------------------------------
;; | Function : Returns the arc sine and arc cosine of a value
;; | Arguments: 'val' - Value to be arc'ed
;; | Returns  : -the result in radians-
;; | Updated  : September 8, 1999
;; | e-mail   : rakesh.rao@4d-technologies.com 
;; | Web      : www.4d-technologies.com
;; | ----------------------------------------------------------------------------


(defun MI_acos( val / tmp )

(setq
	tmp (1- (/ 1.0 (MI_Sqr val)))
	tmp (abs tmp)
)
(atan (sqrt tmp))
)


(defun MI_asin( val / tmp Sign )

(setq tmp (/ 1.0 (1- (/ 1.0 (MI_Sqr val)))))
(if (minusp tmp)
	(setq Sign -1.0)
	(setq Sign  1.0)
)
(setq tmp (abs tmp))
(atan (sqrt tmp))
)