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Solve a system of equations with Wolfram|Alpha?

Posted 8 years ago

I am trying to solve a system of equations which is

E=V*N(x) - r*B*N(x-s), x=(ln(V/r*B)+0.5*s^2)/s and s=(l*E)/V*N(x) 

where N(x) is the cumulative normal density function. From all of these variables my unknowns are V, x and s. So write the code for the Wolfram Alpha in a numerical example

( 2342310000=V*0.5 Erfc[-0.707107 x]-0.97*62076781*0.5 Erfc[-0.707107 (x-s)], x={ln(2342310000/(0.97*62076781))+0.5*s^2}/s, 
  s=(0.568146418550082* 2342310000)/(V*0.5 Erfc[-0.707107 x]) ) 

(note that the N(x) distribution i write it as 0.5*erfv(-0.707107x) as it is described by wolfram alpha http://goo.gl/AN4INU and the outcome that I take is not numerical for the variables V, x and s but it rather transports the equations into this form enter image description here

I think it cannot compute the erfc . If anyone could tell me what I am doing wrong I would be thankful

POSTED BY: hola seniorita
2 Replies

In Mathematica, the error function is Erf https://reference.wolfram.com/language/ref/Erf.html Using that in Wolfram Alpha may help.

POSTED BY: Frank Kampas

Alpha also understands the "complementary erf" function Erfc.

POSTED BY: Daniel Lichtblau
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