TRIG QUESTION

[mackrackit]

Not really RB related, but I need to figure this out for an app I am working on.

My calculator shows:
COSINE of 2 in DEGREES = 0.99939082

COSINE of 2 in RADIANS = -0.41614683

A little more study of radians and found:
COSINE of (2 / 57.29577951) in RADIANS = 0.99939082

But what I can not figure out how to do is:
COSINE of 2 in DEGREES = -0.41614683

[Janet]

From the LB Help File

COS( n )

Description:
This function returns the cosine of the angle n. The angle n should be expressed in radians.

Usage:

for c = 1 to 45
print "The cosine of "; c; " is "; cos(c)
next c

Tip:
There are 2 * pi radians in a full circle of 360 degrees. A formula to convert degrees to radians is: radians = degrees divided by 57.29577951

This code works in both RB and LB, but slightly different numbers after the 7th decimal position.

Print Using("##.#########", Cos(2/57.29577951)) ' Cosine of 2 degrees
Print Using("##.#########", Cos(2)) ' Cosine of 2 radians
End


[mackrackit]

Thanks Janet,

What I am trying to figure out is how to convert the cosine of a number in degrees to radians.

Radians to degrees is easy.

Lets say we had a program that returned the result in degrees and not radians like LB and RB. How would I then convert that to radians?

I am working on a UTM to LatLon converter. I was awake the day they taught us the world is not flat. I have just recently found out working on this the world is not round either. It is kinda EGG shaped. The math is making me look more and more like my avatar

[StefanPendl]

From the LB/JB help file:

function pi()
    pi = asn(1) * 2
end function

function rad2deg(num)
    rad2deg = 90 / asn(1) * num
end function

function deg2rad(num)
    deg2rad = asn(1) / 90 * num
end function

These functions use the internal precision, so they are better then using a constant value.