tim@fonda.ipac.caltech.edu (Tim Conrow) (02/26/91)
Hi all. I'm just coming up to speed on my 48sx and the manual can't answer all the Q's. If someone would either provide an answer to the following, or else give an impatient "It's in the manual!" to tell me to keep looking, I'd appreciate it: If I enter an integral in the form INT(0,Y,A,X) where A is defined as an algebraic I cannot find a way to get A to expand in the integral. It always evaluates to, for the above example, "A*Y". Is there a trick to this. Is the (slow) Equation Writer the only answer? Thanks for your time. -- Tim tim@ipac.caltech.edu
tnan0@CCVAX.IASTATE.EDU (02/26/91)
Tim, You asked about evaluating INT(0,Y,A,X) where A is an algebraic. I set 'A' = 'SIN(COS(T))' for a test... I typed: 'INT(0,Y,A,X)' then I proceeded to hit EVAL several times. After two EVALS, I got: 'A*Y' which is what you kept getting. However, one more EVAL yielded 'SIN(COS(T))*Y' which, I believe, is what you wanted... If there's more to the story, please let me know... ---Xeno P.S. We finally got NEWS on our VAX system, so I can access USENET more directly now... Let's see how this works...
tim@fonda.ipac.caltech.edu (Tim Conrow) (02/26/91)
In article <1991Feb26.021553.18228@news.iastate.edu> tnan0@CCVAX.IASTATE.EDU writes: > You asked about evaluating INT(0,Y,A,X) where A is an algebraic. >I set 'A' = 'SIN(COS(T))' for a test... /\ make this X >I typed: 'INT(0,Y,A,X)' >then I proceeded to hit EVAL several times. After two EVALS, I got: >'A*Y' which is what you kept getting. However, one more EVAL yielded >'SIN(COS(T))*Y' which, I believe, is what you wanted... Almost, but not quite. >If there's more to the story, please let me know... A little more yes ... see below. >---Xeno >P.S. We finally got NEWS on our VAX system, so I can access USENET more >directly now... Let's see how this works... ~~~~~~~~~~ It works fine. In my query, I actually meant something else. In your example modify 'A' to be 'SIN(COS(X))'. Then 'A' must be integrated (which in this example, it couldn't be, except numerically). By fiddling around I finally figured out that the 'SHOW' command is what I want. In the above case one would put the integral on level 2 and the algebraic 'X' in level 1 then execute 'SHOW'. 'A' will then expand into its constituent equation. Fine. I am a little confused, however, as to why one cannot recall the stored value of 'A' into the integral. When I type the integral as far as 'INT(0,Y,)' and then try to recall 'A', I get an invalide syntax error. Oh well; at least it can be done w/o too much pain. -- Tim tim@ipac.caltech.edu
tim@fonda.ipac.caltech.edu (Tim Conrow) (02/27/91)
In article <20530@shlump.nac.dec.com> edp@jareth.enet.dec.com (Eric Postpischil (Always mount a scratch monkey.)) writes: >In article <1991Feb26.030641.17394@nntp-server.caltech.edu>, >tim@fonda.ipac.caltech.edu (Tim Conrow) writes: > >>Fine. I am a little confused, however, as to why one cannot recall the >>stored value of 'A' into the integral. When I type the integral as far as >>'INT(0,Y,)' and then try to recall 'A', I get an invalide syntax error. > >Huh? How are you trying to "recall" A while you are in the middle of typing > in a command line? > -- edp (Eric Postpischil) Well (embarrassed grin), I thought maybe right-shifting the VAR menu key with 'A' on it would do. But no such luck. Live and learn. I think using show command is still the easiest method. Anyone got a better idea? -- Tim tim@ipac.caltech.edu
rbagley@uceng.UC.EDU (Ross A. Bagley) (02/27/91)
> If I enter an integral in the form > > INT(0,Y,A,X) > where A is defined as an algebraic I cannot find a way to get A to expand > in the integral. > tim@ipac.caltech.edu > If you shift to the ALGEBRA directory, the EXPAN function will expand most functions, even inside integrals. For some functions, EXPAN must be used repeatedly, until the function is fully expanded. The COLCT function must then be used to compact the function into a useable form (read collect like terms). I have found however, that this calculator's indefinite integral (symbolic integral) function is very fussy about giving answers for even some of the built in functions, which the manual says it should be able to integrate. Dissapointing, but true. If you have any further problems, or if I didn't answer your question please write again! Ross A Bagley | | | Univ | | of |_____ \____/ | Cinci \______ rbagley@uceng.uc.edu