〖求助〗关于matlab的问题啊 ？？？

狂想001

那位懂matlab的啊
帮个忙
说一下原因啊
syms x a b c
f=a*x^3+x^2-b*x-c
y1=diff(f)
y2=diff(f,a)
y3=diff(f,2)
y4=diff(f,a,2)
上面那段东西是我在书抄的
可是运行的时候却不行啊
  Segmentation violation detected at Fri Jan 12 15:13:55 2007
------------------------------------------------------------------------

Configuration:
  MATLAB Version:  6.5.0.180913a (R13)
  Operating System: Microsoft Windows XP
  Window System:   Version 5.1 (Build 2600: Service Pack 2)
  Processor ID:    x86 Family 15 Model 4 Stepping 1, GenuineIntel
  Virtual Machine:  Java 1.3.1_01 with Sun Microsystems Inc. Java HotSpot(TM) Client VM
   (mixed mode)

Register State:
  EAX = 0000047b  EBX = 0000047b
  ECX = 00df9254  EDX = 23a70785
  ESI = 23a70784  EDI = 00000000
  EBP = 0000047b  ESP = 00df928c
  EIP = 239624f9  FLG = 00010206

Stack Trace:

This error was detected while a MEX-file was running.  If the MEX-file
is not an official MathWorks function, please examine its source code
for errors.  Please consult the External Interfaces Guide for information
on debugging MEX-files.

If it is an official MathWorks function, please
follow these steps in reporting this problem to The MathWorks so
that we have the best chance of correcting it:

  1. Send this crash report to segv@mathworks.com for automated analysis.
    For your convenience, this information has been recorded in:
     C:\DOCUME~1\juntiger\LOCALS~1\Temp\matlab_crash_dump.3280

  2. Also, if the problem is reproducible, send the crash report to
    support@mathworks.com along with:
     - A specific list of steps that will reproduce the problem
     - Any M, MEX, MDL or other files required to reproduce the problem
     - Any error messages displayed prior to this crash report
    A technical support engineer will contact you with further information.

Thank you for your assistance.  Please save your workspace and restart
MATLAB before continuing your work.

Error in ==> G:\建模\toolbox\symbolic\maplemex.dll
Error in ==> G:\建模\toolbox\symbolic\maple.m
On line 116  ==> [result,status] = maplemex(statement);

Error in ==> G:\建模\toolbox\symbolic\@sym\maple.m
On line 74  ==> [result,status] = maple(statement);

Error in ==> G:\建模\toolbox\symbolic\@sym\mpower.m
On line 17  ==>   B = maple(A,'^',p);

Error in ==> G:\建模\work\Untitled4.m
On line 2  ==> f=a*x^3+x^2-b*x-c





那位知道是上面原因啊?
帮个忙啊

kahn

上个学期建模课时还有可能会的
现在就爱莫能助了

綄渼ｄě殘缺

看不懂
无能为力