# Writing an Equation in Excel

A

Hi all,

(-0.928 ln2 (V1) + 13.911 ln (V1) + 27.110) +
(100 - (-0.928 ln2 (V1) + 13.911 ln (V1) + 27.110) * d/100

I'm not sure how to proceed in Excel.

#### joseph_e2

What you have there will *almost* work. You need a * right before each "ln" and you have an unbalanced parentheses.

B

#### barindra75

select any particular cell in excel for V1.
use LOG (F5, base) for your Log function where F5 is the cell number which consist the V1 value and base is the number of base say 10. In case log base e use LN (F5).

sample equation in the particular cell may look like
=(-0.928*LOG(F5, 10) + 13.911*LOG(F5, 10)+27.110)+
(100-(-0.928*LOG(F5, 10)+13.911*LOG(F5, 10)+27.110)*F6/100

where F6 = the cell number where value of d in your equation is placed.
don't forget to put the equal (=) sign at beginning. delete the spaces inside equation.

A

Currently my equation in Excel looks thus:

=IFERROR(((-0,928*(LN(C83))^2+13,911*LN(C83)+27,11)+(100-(-0,928*(LN(C83))^2+13,911*LN(C83)+27,11))*-5/100)/100;"")

C83 is a cell for V1

I would like to know if this form is right or not.

J

#### jbeng

use the LN function for the natural logorarithm
the syntax is LN(number)

u can divide the equation into parts, for easy computation

For the equation check below steps<pre>
Cell A1 is named V1
Cell A2 = 10 (say this is a known input value of V1)
Cell B1 is named d
Cell B2 = 60 = (say this is a known value of d)</pre>
u can divide the equation into parts, for easy computation<pre>
Next Cell C2 ---->> =-0.928*LN(A2)
Cell D2---->> =13.911*LN(A2)+27.11
Cell E2 ---->> =-0.928*A2 *LN(2)+ 13.911*LN(A2) + 27.11
F2 ---->> =B2/100

Next Cell H2 ---->> =(C2+D2)+(100-E2)*F2</pre>
check for errors

Hope This might help. Don't forget the equation signs.