Inverse Trigonometry

[nick2440]

Can anybody help me, I am trying to write an expression in an access query, to preform an inverse trigonometry function. Normally on a calculator it's (cos-1,Tan-1,Sin-1), I believe some systems use Atan/Asin/Acos. Any help would be gratefully welcomed. Thanks.

 

[sfreeman@co.mer]

How do you determine the angle? Is it a stored value?
A little more info please...

Should your resulting data look something like?:

Angle Sin Cos Tan
350 -1.958932825 -1.378464186 -6.135069629
43 -1.831774743 -1.25802596 -4.09229072
23 -1.846220404 -1.271955055 -4.246046094
54 -1.558789049 -0.987993011 -2.517030658
89 -0.139930594 -0.009774321 -1.009774632
76 -0.433892363 -0.092663744 -1.09292988
123 -1.459903491 -0.889334303 -2.232920463

 

[nick2440]

The Angle is what I want the calculation to tell me, by using the measurements from two sides of the right angle, dividing one by the other, then on a scientific calculator you could use the relevent inverse function (sin-1/cos-1/tan-1)

 

[sfreeman@co.mer]

OK, so how do you determine the values needed to determine the angle?

In other words, how are they stored?

 

[Uncle Gizmo]

You may find this sample database provided by Microsoft contains what you need.

 

[sfreeman@co.mer]

OK, assuming that you have a data source [tblAngle] that contains the values needed to determine your angle [Side1] and [Side2], a query might look something like:

SELECT
Cos([Side1]/[Side2])-1
AS InvCos,

Sin([Side1]/[Side2])-1
AS InvSin,

Tan([Side1]/[Side2])-1
AS InvTan

FROM
tblAngle;

results look like:

Side1 Side2 InvCos InvSin InvTan
16 12 -0.764762426697011 -2.80620986366873E-02 3.13172899089315
25 31 -0.307935861928038 -0.278163987601953 4.30189525627305E-02
23 43 -0.139672092699353 -0.490258995253776 -0.407503812882718
54 54 -0.45969769413186 -0.158529015192104 0.557407724654902
89 12 -0.576491355192289 -9.41079381222416E-02 1.13901669537128
76 31 -1.77125890448523 -0.363478435359617 -1.82530206256124
123 42 -1.97739664778533 -0.788586204570292 -1.21630296759125

 

[sfreeman@co.mer]

By the way, I have assumed that your statement regarding the inverse COS results from COS - 1, which I do not believe is correct.

There is a COS(Angle) function within Access, but not an ACOS function.

An ACOS function takes the COS as its parameter and apparently does not give the same result as COS(Angle) -1.

Sorry if this is not much help.

 

[RV]

Access does come with an inverse Tan function, it's called Atan
You could use this function to derive the inversed Cos and Sin function.
Review this link and give it a try:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vblr7/html/vagrpderivedmath.asp

RV