# Board index » delphi » What is Square Root command?

## What is Square Root command?

sqrt()

##### Quote

> Can someone post the command to do a square root.  I'm a newbie and can't find
>  it anywhere.  I don't have the help files at my computer.  Please post it as
>  an RE or email me

> {*word*104}t...@aol.com
> Please note the ZERO in my name
> {*word*104}t0  <---Zero

> Thanx!

## Re:What is Square Root command?

Can someone post the command to do a square root.  I'm a newbie and can't find
it anywhere.  I don't have the help files at my computer.  Please post it as
an RE or email me

{*word*104}t...@aol.com
Please note the ZERO in my name
{*word*104}t0  <---Zero

Thanx!

## Re:What is Square Root command?

On 4 Nov 1997 01:10:51 GMT, {*word*104}t...@aol.com ({*word*104}t0aD) wrote:

##### Quote
>Can someone post the command to do a square root.  I'm a newbie and can't find
> it anywhere.  I don't have the help files at my computer.  Please post it as
> an RE or email me

Maybe you should get a legal version of your compiler ?

Regards
Horst

## Re:What is Square Root command?

##### Quote
> Can someone post the command to do a square root.  I'm a newbie and can't
find
>  it anywhere.  I don't have the help files at my computer.  Please post
it as
>  an RE or email me

This is actually a math question!  Pascal as we know it, does not give a
function to do this, but the mathematical fuctions used for the calculation
in question, are available.

a^n = e^(n log a)   where the base is e. (log base e  is the same as  ln)

which translates to the following in your square root question

x^(1/2) = e^((1/2) ln x)

Function SqrRoot(x : Real) : Real;

Begin
If x = 0 Then
SqrRoot := 0
Else
If x < 0 Then
Halt (Square root is a complex number)
Else
SqrRoot := Exp(0.5 * Ln(x));
End;

Also keep in mind that the answer you get will also work if negative.
e.g. (-2)*(-2) = 4 thus 2 and -2 are both roots of 4.

## Re:What is Square Root command?

##### Quote
>Subject: Re: What is Square Root command?
>From: "BASTARD" <lexli...@iafrica.com>
>Date: Fri, Nov 7, 1997 01:32 EST
>Message-id: <01bceb47\$05cc1f00\$LocalH...@lexlines.iafrica.com>

>> Can someone post the command to do a square root.  I'm a newbie and can't
>find
>>  it anywhere.  I don't have the help files at my computer.  Please post
>it as
>>  an RE or email me

>This is actually a math question!  Pascal as we know it, does not give a
>function to do this, but the mathematical fuctions used for the calculation
>in question, are available.

>a^n = e^(n log a)   where the base is e. (log base e  is the same as  ln)

>which translates to the following in your square root question

>x^(1/2) = e^((1/2) ln x)

>Function SqrRoot(x : Real) : Real;

>Begin
>    If x = 0 Then
>            SqrRoot := 0
>    Else
>            If x < 0 Then
>                    Halt (Square root is a complex number)
>            Else
>                    SqrRoot := Exp(0.5 * Ln(x));
>End;

>Also keep in mind that the answer you get will also work if negative.
>e.g. (-2)*(-2) = 4 thus 2 and -2 are both roots of 4.

Apparently you have never seen the build-in function Sqrt (n).

## Re:What is Square Root command?

##### Quote
BASTARD wrote:

> {*word*104}t0aD <{*word*104}t...@aol.com> wrote in article
> > Can someone post the command to do a square root.  I'm a newbie and can't
> find

[snip]

##### Quote
> This is actually a math question!  Pascal as we know it, does not give a
> function to do this, but the mathematical fuctions used for the calculation
> in question, are available.

[snip]

##### Quote
> which translates to the following in your square root question

> x^(1/2) = e^((1/2) ln x)

[function snipped]

{*word*104}toad might of course also try and look in the manuals for math
functions. Turbo/Borland pascal does implement some of them (after all,
exp() and ln() could also be done by series development.

Your function has the nice property that it is easy to extent to
negative
x, returning complex numbers.
--

Remco Vietor                            Department of Chemistry
re...@chem.gla.ac.uk                       J. Black Building
University of Glasgow
Glasgow G12 8QQ
U.K.

## Re:What is Square Root command?

On Tue, 11 Nov 1997 10:17:36 +0000, Remco Vi?tor

##### Quote
<re...@chem.gla.ac.xukx> wrote:
>BASTARD wrote:

>> {*word*104}t0aD <{*word*104}t...@aol.com> wrote in article
>> > Can someone post the command to do a square root.  I'm a newbie and can't
>> find

>[snip]

>> This is actually a math question!  Pascal as we know it, does not give a
>> function to do this ...

Not true: function sqrt(x: real): real is defined in standard Pascal
and in Turbo Pascal since version 1.

Bob Ferguson

--
J.R. Ferguson, Amsterdam, The Netherlands
e-mail: j.r.fergu...@iname.com

## Re:What is Square Root command?

##### Quote
>Can someone post the command to do a square root.  I'm a newbie and can't find
> it anywhere.  I don't have the help files at my computer.  Please post it as
> an RE or email me

>{*word*104}t...@aol.com
>Please note the ZERO in my name