sin-1

you can easily do SIN, COS and TAN functions in vb,

but how do you do inverse sin or sin-1 ?

ex. sin(30) = 0.5

and sin-1(0.5) = 30

By going through the trouble of searching for Arcsin in MSDN (I'm surprised you didn't since you'll hardly break sweat :) ), I found this.

Derived Math Functions

The following is a list of nonintrinsic math functions that can be derived from the intrinsic math functions:

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 E1)) + Sgn((X) E1) * (2 * Atn(1))
Inverse Cosecant Arccosec(X) = Atn(X / Sqr(X * X - 1)) + (Sgn(X) E1) * (2 * Atn(1))
Inverse Cotangent Arccotan(X) = Atn(X) + 2 * Atn(1)
Hyperbolic Sine HSin(X) = (Exp(X) EExp(-X)) / 2
Hyperbolic Cosine HCos(X) = (Exp(X) + Exp(-X)) / 2
Hyperbolic Tangent HTan(X) = (Exp(X) EExp(-X)) / (Exp(X) + Exp(-X))
Hyperbolic Secant HSec(X) = 2 / (Exp(X) + Exp(-X))
Hyperbolic Cosecant HCosec(X) = 2 / (Exp(X) EExp(-X))
Hyperbolic Cotangent HCotan(X) = (Exp(X) + Exp(-X)) / (Exp(X) EExp(-X))
Inverse Hyperbolic Sine HArcsin(X) = Log(X + Sqr(X * X + 1))
Inverse Hyperbolic Cosine HArccos(X) = Log(X + Sqr(X * X E1))
Inverse Hyperbolic Tangent HArctan(X) = Log((1 + X) / (1 EX)) / 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 E1)) / 2
Logarithm to base N LogN(X) = Log(X) / Log(N)

thanks, I guess that sin-1 is:

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

wotever the hell that is.

I would have thought that sin-1 would have been included into vb, especially as it is a function cn on most decent calculators.

Nope, i'ts this:

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

Probably because it can be derived from the other functions and because it is hardly used. If VB was a program geared for mathematical calculations then we can expect functions for sumations, derivatives, probabilities, combinations, infix/postfix, etc.

If this thread is still used, i was just wondering, what is "E1" supposed to be??

As in: Sqr(X * X E1))

thanks for the list anyway.

Must be a copy paste error

Quote:

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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)

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Its a copy paste error. Look up "derived math functions" in MSDN.