Why this happen in using limit, i cant use syms ? someone help me, i need to do my homework, oh god please.

 syms x h
limit(sin(x)/x)
limit((sin(x + h) - sin(x))/h, h, 0)
Undefined function or variable 'syms'.

Answer 1

[Torsten]

Please execute the "ver" command. You should have something like

Symbolic Math Toolbox                                 Version 6.1        (R2014b)

as part of the output. If not, that is the answer, you do not have the Symbolic Math Toolbox. If you do have, let's see what

which syms -all

returns

[An Chan]

 >> which syms -all
'syms' not found.

[An Chan]

 MATLAB Version: 9.0.0.341360 (R2016a)
MATLAB License Number: 123456
Operating System: Microsoft Windows 10 Pro Version 10.0 (Build 15063)
Java Version: Java 1.7.0_60-b19 with Oracle Corporation Java HotSpot(TM) 64-Bit Server VM mixed mode
----------------------------------------------------------------------------------------------------
MATLAB                                                Version 9.0         (R2016a)
Aerospace Blockset                                    Version 3.17        (R2016a)
Aerospace Toolbox                                     Version 2.17        (R2016a)
Antenna Toolbox                                       Version 2.0         (R2016a)
Audio System Toolbox                                  Version 1.0         (R2016a)
Bioinformatics Toolbox                                Version 4.6         (R2016a)
Communications System Toolbox                         Version 6.2         (R2016a)
Control System Toolbox                                Version 10.0        (R2016a)
Curve Fitting Toolbox                                 Version 3.5.3       (R2016a)
DO Qualification Kit                                  Version 3.1         (R2016a)
DSP System Toolbox                                    Version 9.2         (R2016a)
Data Acquisition Toolbox                              Version 3.9         (R2016a)
Database Toolbox                                      Version 6.1         (R2016a)
Datafeed Toolbox                                      Version 5.3         (R2016a)
Econometrics Toolbox                                  Version 3.4         (R2016a)
Embedded Coder                                        Version 6.10        (R2016a)
Filter Design HDL Coder                               Version 3.0         (R2016a)
Financial Instruments Toolbox                         Version 2.3         (R2016a)
Financial Toolbox                                     Version 5.7         (R2016a)
Fixed-Point Designer                                  Version 5.2         (R2016a)
Fuzzy Logic Toolbox                                   Version 2.2.23      (R2016a)
Global Optimization Toolbox                           Version 3.4         (R2016a)
HDL Coder                                             Version 3.8         (R2016a)
HDL Verifier                                          Version 5.0         (R2016a)
IEC Certification Kit                                 Version 3.7         (R2016a)
Image Acquisition Toolbox                             Version 5.0         (R2016a)
Image Processing Toolbox                              Version 9.4         (R2016a)
Instrument Control Toolbox                            Version 3.9         (R2016a)
LTE System Toolbox                                    Version 2.2         (R2016a)
MATLAB Coder                                          Version 3.1         (R2016a)
MATLAB Compiler                                       Version 6.2         (R2016a)
MATLAB Compiler SDK                                   Version 6.2         (R2016a)
MATLAB Distributed Computing Server                   Version 6.8         (R2016a)
MATLAB Report Generator                               Version 5.0         (R2016a)
Mapping Toolbox                                       Version 4.3         (R2016a)
Model Predictive Control Toolbox                      Version 5.2         (R2016a)
Model-Based Calibration Toolbox                       Version 5.1         (R2016a)
Neural Network Toolbox                                Version 9.0         (R2016a)
OPC Toolbox                                           Version 4.0.1       (R2016a)
Optimization Toolbox                                  Version 7.4         (R2016a)
Parallel Computing Toolbox                            Version 6.8         (R2016a)
Partial Differential Equation Toolbox                 Version 2.2         (R2016a)
Phased Array System Toolbox                           Version 3.2         (R2016a)
Polyspace Bug Finder                                  Version 2.1         (R2016a)
Polyspace Code Prover                                 Version 9.5         (R2016a)
RF Toolbox                                            Version 3.0         (R2016a)
Robotics System Toolbox                               Version 1.2         (R2016a)
Robust Control Toolbox                                Version 6.1         (R2016a)
Signal Processing Toolbox                             Version 7.2         (R2016a)
SimBiology                                            Version 5.4         (R2016a)
SimEvents                                             Version 5.0         (R2016a)
SimRF                                                 Version 5.0         (R2016a)
Simscape                                              Version 4.0         (R2016a)
Simscape Driveline                                    Version 2.10        (R2016a)
Simscape Electronics                                  Version 2.9         (R2016a)
Simscape Fluids                                       Version 2.0         (R2016a)
Simscape Multibody                                    Version 4.8         (R2016a)
Simscape Power Systems                                Version 6.5         (R2016a)
Simulink Coder                                        Version 8.10        (R2016a)
Simulink PLC Coder                                    Version 2.1         (R2016a)
Simulink Report Generator                             Version 5.0         (R2016a)
Spreadsheet Link                                      Version 3.2.5       (R2016a)
System Identification Toolbox                         Version 9.4         (R2016a)

[Torsten]

So it seems you don't have the Symbolic Toolbox licenced.

Best wishes

Torsten.

[An Chan]

OMG dont just say Best wished. @@ i really need help

[Arthur Goldsipe]

You don't have a license to the Symbolic Math Toolbox, so there's nothing else we can do to help you. If this software is required for your homework, then I suggest talking to your instructor or fellow students to learn how to obtain the required software for your course.