Inverse Trig

[qbasicking]

Its been a while...
How do you find the Inverse Sine of a value in Qbasic?

 

[dpaulson]

Found this


' define an inverse sine function
'
DEF FNasin (x)
c = SQR(1 - x * x)
FNasin = ATN(x / c)
END DEF
David Paulson

 

[agual]

You should catch the error conditions otr the function will break:
pi=4*ATN(1)
Function asin (x)
    select case abs(x)
case is >1: asin=1e30 '<it indicates an erroneous input!
case 1: if x>0 then asin =pi/2 else asin=-pi/2
case else: c= SQR(1 - x * x)
     asin = ATN(x / c)
end select
END Function Antoni

http://www.geocities.com/antonigual/index.html

 

[CubeE101]

Inverse Sine
Arcsin(X) = Atn(X / Sqr(-X * X + 1))

From VB Documentation:
(...this should take care of most of your trig stuff...)

Function
Derived equivalents

Secant
Sec(X) = 1 / Cos(X)

Cosecant
Cosec(X) = 1 / Sin(X)

Cotangent
Cotan(X) = 1 / Tan(X)

Inverse Sine
Arcsin(X) = Atn(X / Sqr(-X * X + 1))

Inverse Cosine
Arccos(X) = Atn(-X / Sqr(-X * X + 1)) + 2 * Atn(1)

Inverse Secant
Arcsec(X) = Atn(X / Sqr(X * X – 1)) + Sgn((X) – 1) * (2 * Atn(1))

Inverse Cosecant
Arccosec(X) = Atn(X / Sqr(X * X - 1)) + (Sgn(X) – 1) * (2 * Atn(1))

Inverse Cotangent
Arccotan(X) = Atn(X) + 2 * Atn(1)

Hyperbolic Sine
HSin(X) = (Exp(X) – Exp(-X)) / 2

Hyperbolic Cosine
HCos(X) = (Exp(X) + Exp(-X)) / 2

Hyperbolic Tangent
HTan(X) = (Exp(X) – Exp(-X)) / (Exp(X) + Exp(-X))

Hyperbolic Secant
HSec(X) = 2 / (Exp(X) + Exp(-X))

Hyperbolic Cosecant
HCosec(X) = 2 / (Exp(X) – Exp(-X))

Hyperbolic Cotangent
HCotan(X) = (Exp(X) + Exp(-X)) / (Exp(X) – Exp(-X))

Inverse Hyperbolic Sine
HArcsin(X) = Log(X + Sqr(X * X + 1))

Inverse Hyperbolic Cosine
HArccos(X) = Log(X + Sqr(X * X – 1))

Inverse Hyperbolic Tangent
HArctan(X) = Log((1 + X) / (1 – X)) / 2

Inverse Hyperbolic Secant
HArcsec(X) = Log((Sqr(-X * X + 1) + 1) / X)

Inverse Hyperbolic Cosecant
HArccosec(X) = Log((Sgn(X) * Sqr(X * X + 1) + 1) / X)

Inverse Hyperbolic Cotangent
HArccotan(X) = Log((X + 1) / (X – 1)) / 2

Logarithm to base N
LogN(X) = Log(X) / Log(N)

Good Luck -Josh Have Fun, Be Young... Code BASIC
-Josh Stribling

http://cubee.topcities.com

 

[CubeE101]

Note: The above are in algebraic notation...

to use in a program...

This:

Inverse Sine
Arcsin(X) = Atn(X / Sqr(-X * X + 1))

Should look like this:

Function Arcsin(X as double)
  Arcsin = Atn(X / Sqr(-X * X +1))
End Function

(Just 4 Tha Record ;-)) Have Fun, Be Young... Code BASIC
-Josh Stribling

http://cubee.topcities.com