Operation order - bug or me?

**andyHefei** · 08-21-2011, 09:23 PM

dear all,

i really do not understand if it's me doing something silly of a special feature of Excel.
I do not consider myself a newbie.

I solved my problem, but I was wondering if there are some links with literature explaining a bit better these little features..

I tried 2 expressions:

=(-D3^2+B3^2+C3^2)/(2*B3*C3) (Exp1)

and

=(B3^2+C3^2-D3^2)/(2*B3*C3) (Exp2)

with (tested) integer and double numbers in B,C,D fields

the result is different, with the expression (Exp2) giving the correct result.

then i tried:

=(-(D3^2)+B3^2+C3^2)/(2*B3*C3) (Exp3)

and finally got the same result as (Exp2)..

so maybe I guess Excel change the sign of the field D3 before it makes it square..

But then why (Exp2) is working???

Do you know some links/literature explaining things like this, about how Excel handle fields in case of multiple math calculations?

Thanks!

**shg** · 08-21-2011, 11:34 PM

The unary negation operator is the highest precedence among arithmetic operators; -3^2 = 9, not -9

**andyHefei** · 08-21-2011, 11:37 PM

but then why (Exp2) is ok?

=(B3^2+C3^2-D3^2)/(2*B3*C3) (Exp2)

is that because here the "-" is arithmetic subtraction and not unary negation operator?

where can i find a lit of these priorities?

thx!