# 2.2 Completing the basics  (Page 3/6)

 Page 3 / 6

`<<setiosflags(ios::oct)<<15<<endl`

`<<"The hexadecimal (base 16) value of 15 is "`

`<<setiosflags(ios::hex)<<15<<endl;`

`return 0;`

`}`

The output of the above program:

The decimal (base 10) value of 15 is 15

The octal (base 8) value of 15 is 17

The hexadecimal (base 16) value of 15 is f

To designate an octal integer constant, the number must have a leading 0 . Hexadecimal number are denoted using a leading 0x .

Example

`// Octal and hexadecimal integer constant`

`#include<iostream.h>`

`int main()`

`{`

`cout<<"The decimal value of 025 is "<<025<<endl`

`<<"The decimal value of 0x37 is "<<0x37<<endl;`

`return 0;`

`}`

The output of the above program:

The decimal value of 025 is 21

The decimal value of 0x37 is 55

## Using mathematical library functions

Although addition, subtraction, multiplication and division are easily accomplished using C++’s arithmetic operators, no such operators exist for finding the square root of a number or determining trigonometric values. To facilitate such calculations, C++ provides standard library functions that can be included in a program.

Functions are normally called by writing the name of the function, followed by a left parenthesis, followed by the argument (or a comma-separated list of arguments) of the function, followed by a right parenthesis. For example, a programmer desiring to calculate and print the square root of 900.0 might write:

`cout<<sqrt(900.0);`

When this statement is executed, the math library function sqrt is called to calculate the square root of the number contained in the parentheses (900.0). The number 900.0 is the argument of the sqrt function. The preceding statement would print 30. The sqrt function takes an argument of type double and returns a result of type double.

If your program uses mathematic function sqrt(), it should have the preprocessor command #include<math.h> in the beginning of the program. This makes a mathematical library accessible. Below are some commonly used mathematical functions provided in C++.

Except abs(a), the functions all take an argument of type double and return a value of type double.

Example

`// this program calculates the area of a triangle`

`// given its three sides`

`#include<iostream.h>`

`#include<math.h>`

`int main()`

`{`

`double a,b,c, s;`

`a = 3;`

`b = 4;`

`c = 5;`

`s = (a+b+c)/2.0;`

`area = sqrt(s*(s-a)*(s-b)*(s-c));`

`cout<<"The area of the triangle = "<<area<<endl;`

`return 0;`

`}`

The output of the above program:

The area of the triangle = 6.0

## Casts

We have already seen the conversion of an operand’s data type within mixed-mode expressions and across assignment operators. In addition to these implicit data type conversions that are automatically made within mixed-mode expressions and assignment, C++ also provides for explicit user-specified type conversion. This method of type conversion is called casting . The word cast is used in the sense of “casting into a mold.”

Casting or type casting , copies the value contained in a variable of one data type into a variable of another data type.

The C++ syntax for casting variables is

`variable = new_type( old_variable);`

What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
why we need to study biomolecules, molecular biology in nanotechnology?
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
why?
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
research.net
kanaga
sciencedirect big data base
Ernesto
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
how did you get the value of 2000N.What calculations are needed to arrive at it
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