# Essentials  (Page 2/4)

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MATLAB accepts log10 for common (base 10) logarithm. To find the log of 10, type in log10(10) and press enter, (ans = 1).

Practice the following examples to familiarize yourself with the common mathematical functions. Be sure to read the relevant help and doc pages for functions that are not self explanatory.

Calculate the following quantities:

1. $\frac{2^{3}}{3^{2}-1}$ ,
2. $5^{0.5}-1$
3. $\frac{\pi }{4}d^{2}$ for d=2

MATLAB inputs and outputs are as follows:

1. $\frac{2^{3}}{3^{2}-1}$ is entered by typing 2^3/(3^2-1) (ans = 1)
2. $5^{0.5}-1$ is entered by typing sqrt(5)-1 (ans = 1.2361)
3. $\frac{\pi }{4}d^{2}$ for d=2 is entered by typing pi/4*2^2 (ans = 3.1416)

Calculate the following exponential and logarithmic quantities:

1. $e^{2}$
2. $\ln 5^{10}$
3. $\lg 10^{5}$

MATLAB inputs and outputs are as follows:

1. exp(2) (ans = 7.3891)
2. log((5^10)) (ans = 16.0944)
3. log10(10^5) (ans = 5)

Calculate the following trigonometric quantities:

1. $\cos \left(\frac{\pi }{6}\right)$
2. $\tan 45$
3. $\sin \pi +\cos 45$

MATLAB inputs and outputs are as follows:

1. cos(pi/6) (ans = 0.8660)
2. tan(45*pi/180) (ans = 1.0000)
3. sin(pi)+cos(45*pi/180) (ans = 0.7071)

## The format Function

The format function is used to control how the numeric values are displayed in the Command Window. The short format is set by default and the numerical results are displayed with 4 digits after the decimal point (see the examples above). The long format produces 15 digits after the decimal point.

Calculate $\theta =\tan \left(\frac{\pi }{3}\right)$ and display results in short and long formats.

The short format is set by default:

>>theta=tan(pi/3) theta =1.7321>>

And the long format is turned on by typing format long :

>>theta=tan(pi/3) theta =1.7321>>format long>>theta theta =1.732050807568877

## Variables

In MATLAB, a named value is called a variable. MATLAB comes with several predefined variables. For example, the name pi refers to the mathematical quantity π, which is approximately pi ans = 3.1416

MATLAB is case-sensitive, which means it distinguishes between upper- and lowercase letters (e.g. data, DATA and DaTa are three different variables). Command and function names are also case-sensitive. Please note that when you use the command-line help, function names are given in upper-case letters (e.g., CLEAR) only to emphasize them. Do not use upper-case letters when running functions and commands.

## Declaring variables

Variables in MATLAB are generally represented as matrix quantities. Scalars and vectors are special cases of matrices having size 1x1 (scalar), 1xn (row vector) or nx1 (column vector).

## Declaration of a scalar

The term scalar as used in linear algebra refers to a real number. Assignment of scalars in MATLAB is easy, type in the variable name followed by = symbol and a number:

a = 1

## Declaration of a row vector

Elements of a row vector are separated with blanks or commas.

Let's type the following at the command prompt:

b = [1 2 3 4 5]

We can also use the New Variable button to assign a row vector. In the tool strip, select Home>New Variable. This action will create a variable called unnamed which is displayed in the workspace. By clicking on the title unnamed, we can rename it to something more descriptive. By double-clicking on the variable, we can open the Variable Editor and type in the values into spreadsheet looking table.

anyone know any internet site where one can find nanotechnology papers?
research.net
kanaga
Introduction about quantum dots in nanotechnology
what does nano mean?
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
it is a goid question and i want to know the answer as well
Maciej
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
for screen printed electrodes ?
SUYASH
What is lattice structure?
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
what's the easiest and fastest way to the synthesize AgNP?
China
Cied
types of nano material
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
what is the k.e before it land
Yasmin
what is the function of carbon nanotubes?
Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
how did you get the value of 2000N.What calculations are needed to arrive at it
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