Formula returns incorrect result

users
#1

I'm trying to
      calculate the Equation of Time (EoT) to determine the difference
      between LAN (Local Apparent Noon) and GMT/UT-1  Greenwich Mean
      Time.  Then I want to plot the EoT curve (a project for later, not
      now)The following is the formula I use on my calculator.  The formula
      gives a "close enough" EoT9.87xsin(2x360(3-81)÷365)-7.67 x sin(360(3-81)÷365+78.7)=
      -4.584625249 (or.... -4 minutes 35.1 seconds...plus or minus)Calc doesn't give the same answer.  Here's the formula in calc;=9.87*SIN(RADIANS(2*360*(3-81)/365)-7.67*SIN(RADIANS(360*(3-81)/365+78.7)))The answer it returns is: -2.14883666659093Can you tell me what the correct layout of the format in calc is?Thank you,Peter

#2

No idea how this
      gibberish got returned
I'm
          trying to calculate the Equation of Time (EoT) to determine
          the difference between LAN (Local Apparent Noon) and GMT/UT-1 
          Greenwich Mean Time.  Then I want to plot the EoT curve (a
          project for later, not now)The following is the formula I use on my calculator.  The
          formula gives a "close enough" EoT9.87xsin(2x360(3-81)÷365)-7.67 x sin(360(3-81)÷365+78.7)=
          -4.584625249 (or.... -4 minutes 35.1 seconds...plus or minus)Calc doesn't give the same answer.  Here's the formula in
          calc;=9.87*SIN(RADIANS(2*360*(3-81)/365)-7.67*SIN(RADIANS(360*(3-81)/365+78.7)))The answer it returns is: -2.14883666659093Can you tell me what the correct layout of the format in calc
          is?Thank you,Peter

#3

I'm trying to calculate the Equation of Time (EoT) to determine the difference between LAN (Local Apparent Noon) and GMT/UT-1 Greenwich Mean Time. Then I want to plot the EoT curve (a project for later, not now) The following is the formula I use on my calculator. The formula gives a "close enough" EoT
9.87xsin(2x360(3-81)÷365)-7.67 x sin(360(3-81)÷365+78.7)
=-4.584625249 (or.... -4 minutes 35.1 seconds...plus or minus)
Calc doesn't give the same answer.

It does if you translate the formula correctly.

Here's the formula in calc;
=9.87*SIN(RADIANS(2*360*(3-81)/365)-7.67*SIN(RADIANS(360*(3-81)/365+78.7)))
The answer it returns is: -2.14883666659093
Can you tell me what the correct layout of the format in calc is?

You have failed to close one set of parentheses - at the end of the first SIN() expression (perhaps you forgot to close the first RADIANS() expression, in fact) - but then added a spare closing parenthesis at the end of your expression. The effect is that the first SIN() expression includes all of the second part of your formula.

Try:
=9.87*SIN(RADIANS(2*360*(3-81)/365))-7.67*SIN(RADIANS(360*(3-81)/365+78.7))
instead.

I trust this helps.

Brian Barker

#4

Count the '(' and the ')'

=9.87*SIN(RADIANS(2*360*(3-81)/365)-7.67*SIN(RADIANS(360*(3-81)/365+78.7)))

should be

=9.87*SIN(RADIANS(2*360*(3-81)/365))-7.67*SIN(RADIANS(360*(3-81)/365+78.7))