Trigonometry in Excel

[Serge]

The formula below gives a result of 79.935 degrees using calculator
cos A = (b² + c²) - a² / 2bc
a=25.0 in A57
b=21.5407 in B57
c=17.0 in C57

This formula below has error which I cannot fix.
I have been trying for a while with no luck.
It could be that I'm trying to approch it the same way as a calculator.
In E57
=IF(OR(A57="",B57="",C57=""),0,DEGREES(ACOS(B57^+C57^)-A57^/2*B57*C57)))

Or in E57 =IF(COUNT(A57:C57)<3,0),0,DEGREES(ACOS(B57^+C57^)-A57^/2*B57*C57)))
My answer should be 79.935 degrees
Does someone have an answer for this puzzle?
Many thanks in advance.
Serge

[Dana DeLouis]

Hi. I think the use of ( ) are slightly off. See if this work:
I've used Range names. Note that "c" has to be "c_" in Excel.

=DEGREES(ACOS((b^2+c_^2-a^2) / (2*b*c_)))

Returns your solution of 79.935.
--
HTH. :>)
Dana DeLouis
Windows XP, Office 2003


"Serge" <Serge@discussions.microsoft.com> wrote in message
news:511709C7-8579-4E29-AB71-7BA79A4C992E@microsoft.com...
> The formula below gives a result of 79.935 degrees using calculator
> cos A = (b² + c²) - a² / 2bc
> a=25.0 in A57
> b=21.5407 in B57
> c=17.0 in C57
>
> This formula below has error which I cannot fix.
> I have been trying for a while with no luck.
> It could be that I'm trying to approch it the same way as a calculator.
> In E57
> =IF(OR(A57="",B57="",C57=""),0,DEGREES(ACOS(B57^+C57^)-A57^/2*B57*C57)))
>
> Or in E57
> =IF(COUNT(A57:C57)<3,0),0,DEGREES(ACOS(B57^+C57^)-A57^/2*B57*C57)))
> My answer should be 79.935 degrees
> Does someone have an answer for this puzzle?
> Many thanks in advance.
> Serge
>
>
>

[Serge]

Hello Dana,
Thank you for your reply.
My formula looks as follows now:
=IF(OR(A57="",B57="",C57=""),0,DEGREES(ACOS((B57^2+C57^2-A57^2) /
(2*B57*C57))))
And it works well thank you very much.
I see that I missed the '2' next to the karet. I was not thinking.
Can you explain to me your version & the underscore next to the 'c'.
If you don't have time it's ok.
Anyway I'm very happy for your help.

Much thanks
Serge

"Dana DeLouis" wrote:

> Hi. I think the use of ( ) are slightly off. See if this work:
> I've used Range names. Note that "c" has to be "c_" in Excel.
>
> =DEGREES(ACOS((b^2+c_^2-a^2) / (2*b*c_)))
>
> Returns your solution of 79.935.
> --
> HTH. :>)
> Dana DeLouis
> Windows XP, Office 2003
>
>
> "Serge" <Serge@discussions.microsoft.com> wrote in message
> news:511709C7-8579-4E29-AB71-7BA79A4C992E@microsoft.com...
> > The formula below gives a result of 79.935 degrees using calculator
> > cos A = (b² + c²) - a² / 2bc
> > a=25.0 in A57
> > b=21.5407 in B57
> > c=17.0 in C57
> >
> > This formula below has error which I cannot fix.
> > I have been trying for a while with no luck.
> > It could be that I'm trying to approch it the same way as a calculator.
> > In E57
> > =IF(OR(A57="",B57="",C57=""),0,DEGREES(ACOS(B57^+C57^)-A57^/2*B57*C57)))
> >
> > Or in E57
> > =IF(COUNT(A57:C57)<3,0),0,DEGREES(ACOS(B57^+C57^)-A57^/2*B57*C57)))
> > My answer should be 79.935 degrees
> > Does someone have an answer for this puzzle?
> > Many thanks in advance.
> > Serge
> >
> >
> >
>
>
>

[Dana DeLouis]

> Can you explain to me your version & the underscore next to the 'c'.

Hi. I was just using Range Names. I gave A57 the name "a"...etc. The
letter "c" is a little different in Excel. The letters "c" and "r" are not
valid names in Excel. However, the letter "c_" is valid.

> I see that I missed the '2' next to the karat

I thought the following version is interesting as it avoids the power
symbol.
However, it turns out to be a longer equation. Darn!

=IF(COUNTBLANK(A57:C57)>0,0,
DEGREES(ACOS(1+SUMX2MY2(B57-C57,A57) / (2*B57*C57))))

--
HTH. :>)
Dana DeLouis
Windows XP, Office 2003


"Serge" <Serge@discussions.microsoft.com> wrote in message
news:6703986C-D2E8-463D-9F02-4006904173BE@microsoft.com...
> Hello Dana,
> Thank you for your reply.
> My formula looks as follows now:
> =IF(OR(A57="",B57="",C57=""),0,DEGREES(ACOS((B57^2+C57^2-A57^2) /
> (2*B57*C57))))
> And it works well thank you very much.
> I see that I missed the '2' next to the karet. I was not thinking.
> Can you explain to me your version & the underscore next to the 'c'.
> If you don't have time it's ok.
> Anyway I'm very happy for your help.
>
> Much thanks
> Serge
>
> "Dana DeLouis" wrote:
>
>> Hi. I think the use of ( ) are slightly off. See if this work:
>> I've used Range names. Note that "c" has to be "c_" in Excel.
>>
>> =DEGREES(ACOS((b^2+c_^2-a^2) / (2*b*c_)))
>>
>> Returns your solution of 79.935.
>> --
>> HTH. :>)
>> Dana DeLouis
>> Windows XP, Office 2003
>>
>>
>> "Serge" <Serge@discussions.microsoft.com> wrote in message
>> news:511709C7-8579-4E29-AB71-7BA79A4C992E@microsoft.com...
>> > The formula below gives a result of 79.935 degrees using calculator
>> > cos A = (b² + c²) - a² / 2bc
>> > a=25.0 in A57
>> > b=21.5407 in B57
>> > c=17.0 in C57
>> >
>> > This formula below has error which I cannot fix.
>> > I have been trying for a while with no luck.
>> > It could be that I'm trying to approch it the same way as a calculator.
>> > In E57
>> > =IF(OR(A57="",B57="",C57=""),0,DEGREES(ACOS(B57^+C57^)-A57^/2*B57*C57)))
>> >
>> > Or in E57
>> > =IF(COUNT(A57:C57)<3,0),0,DEGREES(ACOS(B57^+C57^)-A57^/2*B57*C57)))
>> > My answer should be 79.935 degrees
>> > Does someone have an answer for this puzzle?
>> > Many thanks in advance.
>> > Serge
>> >
>> >
>> >
>>
>>
>>

[Ron Rosenfeld]

On Thu, 25 May 2006 18:35:01 -0700, Serge <Serge@discussions.microsoft.com>
wrote:

>The formula below gives a result of 79.935 degrees using calculator
>cos A = (b² + c²) - a² / 2bc
>a=25.0 in A57
>b=21.5407 in B57
>c=17.0 in C57
>
>This formula below has error which I cannot fix.
>I have been trying for a while with no luck.
>It could be that I'm trying to approch it the same way as a calculator.
>In E57
>=IF(OR(A57="",B57="",C57=""),0,DEGREES(ACOS(B57^+C57^)-A57^/2*B57*C57)))
>
>Or in E57 =IF(COUNT(A57:C57)<3,0),0,DEGREES(ACOS(B57^+C57^)-A57^/2*B57*C57)))
>My answer should be 79.935 degrees
>Does someone have an answer for this puzzle?
>Many thanks in advance.
>Serge
>
>

You just need to properly arrange your parentheses:

=IF(COUNT(A57:C57)=3,DEGREES(ACOS((B57^2+C57^2-A57^2)/(2*B57*C57))),0)

--ron

[Serge]

Hello Ron,
I tried your formula and it works well also. I need to study this one.
Thank you for your input. I learn something different.
Serge

"Ron Rosenfeld" wrote:

> On Thu, 25 May 2006 18:35:01 -0700, Serge <Serge@discussions.microsoft.com>
> wrote:
>
> >The formula below gives a result of 79.935 degrees using calculator
> >cos A = (b² + c²) - a² / 2bc
> >a=25.0 in A57
> >b=21.5407 in B57
> >c=17.0 in C57
> >
> >This formula below has error which I cannot fix.
> >I have been trying for a while with no luck.
> >It could be that I'm trying to approch it the same way as a calculator.
> >In E57
> >=IF(OR(A57="",B57="",C57=""),0,DEGREES(ACOS(B57^+C57^)-A57^/2*B57*C57)))
> >
> >Or in E57 =IF(COUNT(A57:C57)<3,0),0,DEGREES(ACOS(B57^+C57^)-A57^/2*B57*C57)))
> >My answer should be 79.935 degrees
> >Does someone have an answer for this puzzle?
> >Many thanks in advance.
> >Serge
> >
> >
>
> You just need to properly arrange your parentheses:
>
> =IF(COUNT(A57:C57)=3,DEGREES(ACOS((B57^2+C57^2-A57^2)/(2*B57*C57))),0)
>
> --ron
>