Student Support Forum: 'Limit returns unevaluated input' topicStudent Support Forum > General > "Limit returns unevaluated input"

 < Previous Comment | Next Comment > Help | Reply To Comment | Reply To Topic
 Author Comment/Response jf 06/23/12 6:39pm In Response To 'Re: Re: Re: Re: Re: Limit returns unevaluated i...'---------Is your Assuming covering enough of the expression? In[2]:= soln=Assuming[{b0>b1,b1>0,m0>m1,x\[Element]Reals&&n\[Element]Integers},Simplify[Limit[(1/Sqrt[2 \[Pi]])((E^(-(((b0^2-b1^2) (m0-m1) (-b1^2 (m0+m1 (-1+n)+3 m0 n-4 n x)+b0^2 (m0-m1+m0 n+3 m1 n-4 n x))-2 n (b1^2 (m0-x)+b0^2 (-m1+x))^2 PolyGamma[0,(b0^2+b1^2 (-1+n))/(b0^2-b1^2)]+2 n (b1^2 (m0-x)+b0^2 (-m1+x))^2 PolyGamma[0,(-b1^2+b0^2 (1+n))/(b0^2-b1^2)])/(4 (b0-b1)^3 (b0+b1)^3)))/(Sqrt[((b0^2-b1^2)/n)^n Pochhammer[1+(b1^2 n)/(b0^2-b1^2),n]]))^((1/n))),n->Infinity]]] Out[2]= (1/Sqrt[2*Pi])*((b1^(b1^2/(b0^2 - b1^2))* E^((2*b0^4 + b1^2*(2*b1^2 + (m0 - m1)*(3*m0 + m1 - 4*x)) - b0^2*(4*b1^2 + (m0 - m1)*(m0 + 3*m1 - 4*x)))/(4*(b0 - b1)^2*(b0 + b1)^2)))/ (b0^(b0^2/(b0^2 - b1^2))*(b0/b1)^((b1^2*(m0 - x) + b0^2*(-m1 + x))^2/ ((b0 - b1)^3*(b0 + b1)^3)))) For sample values of these parameters, In[3]:= soln /. {b1 ->1, b0->3, m0->2,m1->0} Out[3]= (3^(-(9/8) - (1/512)*(2 + 8*x)^2)* E^((1/256)*(164 - 9*(4 + 2*(2 - 4*x)) + 2*(6 - 4*x))))/Sqrt[2*Pi] Try a few values of x. In[4]:= % /. {{x->0.},{x->1.},{x->10.}} Out[4]= {0.172525, 0.180288, 1.14914 10^-6 } (Oops- two of those x's do not meet the assumption "x is between m0 and m1".) In[5]:= \$Version Out[5]= 8.0 for Mac OS X x86 (64-bit) (October 5, 2011) Attachment: sf29120.nb, URL: ,

 Subject (listing for 'Limit returns unevaluated input') Author Date Posted Limit returns unevaluated input igor igel 06/20/12 06:17am Re: Limit returns unevaluated input Bill Simpson 06/20/12 11:47am Re: Re: Limit returns unevaluated input jf 06/21/12 10:50am Re: Re: Re: Limit returns unevaluated input igor igel 06/21/12 1:41pm Re: Re: Re: Re: Limit returns unevaluated input jf 06/21/12 1:56pm Re: Re: Re: Re: Re: Limit returns unevaluated i... igor igel 06/22/12 09:13am Re^6: Limit returns unevaluat... jf 06/23/12 6:39pm Re: Limit returns unevaluated input igor igel 07/14/12 03:20am
 < Previous Comment | Next Comment > Help | Reply To Comment | Reply To Topic