# Fonction math ^

hello everyone, I can't seem to input this formula with APP's MATH functions:

= 100 ^ - ((F1-F2) / 5)

cordially

Stephane

See this example :

or perhaps?....

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Also
100 ^ ((F2-F1) / 5)

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Merci pour votre rĂ©ponse, cependant cela ne me donne pas la bonne rĂ©ponse : cela me retourne 0.39811
Il s'agit d'une Ă©quation pour le calcul de magnitude
A la base l'equation est : M1-M2 = -2.5 log(F1/F2) => si F1=2 et F2=3, avec un Ă©cart de 1 le rĂ©sultat et 2.51

Je continu Ă  chercher, pourtant cela me semble simple car cela marche avec excel

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Merci pour votre rĂ©ponse, cependant cela ne me donne pas la bonne rĂ©ponse : cela me retourne 10
Il s'agit d'une Ă©quation pour le calcul de magnitude
A la base l'equation est : M1-M2 = -2.5 log(F1/F2) => si F1=2 et F2=3, avec un Ă©cart de 1 le rĂ©sultat et 2.51

Je continu Ă  chercher, pourtant cela me semble simple car cela marche avec excel

Be careful with the logarithm, in App Inventor "log" is natural logarithm.

log10(X) = logN(X) / 2.3026

In the expression you are using, "log" is logarithm to base 10

http://obswww.unige.ch/Questions_Reponses/R7.html

Like this ?

Hello TIMAI2

which math extension are you using for your example?
I can't find in my blocks

thank you

It may be that I have used external inputs from the right click menu

Hello

I built the calculation block which should correspond to the mathematical function it does not give the same result!
I keep looking, yet it should be easy to do !!!

Stephane

If you meant this

there is no extension, this is a built procedure using default blocks

Hello

With excel I use:
X = 100 ^ - ((F1-F2) / 5)
If F1 = 2 and F3 = 3
X = 2.5119

I'll find it !!

Well, these blocks are what i provided a few posts before, and they return that result.....

Thank you it's Ok

I had to reverse an operator in the assembly of the block.
In the meantime, I have found another solution, but yours seems more conventional to me

I am new to the use of the app I discover its philosophy
This will be used for a calculator for astronomy calculations

thank you for everything

Stephane
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