Calling Marv Klotz (Math calculati

[gbritnell]

My math is a little rusty in the area of order of operations. I know that anything in parenthesis has to be performed first and I know that after everything is performed I have to find the square root but I don't know what the 1- means and should it come before squaring. Equation attached.
gbritnell

[stevehuckss396]

My math is a little rusty in the area of order of operations. I know that anything in parenthesis has to be performed first and I know that after everything is performed I have to find the square root but I don't know what the 1- means and should it come before squaring. Equation attached.
gbritnell

I believe it is just that 1 minus

1 minus all the hocus pocus to the right of it.

[stevehuckss396]

A = 2.77/12.92

B = A^2

C = 1-B

D = Sqrt(C)

D = 0.97674664063


Being this is a one question test, I got an "A" or an "F"

What did I get?

[mklotz]

Yup, Steve nailed it.  Give him an 'A'.

[gbritnell]

Thanks Steve and Marv but I still can't get it to match the sample calculation. This is from Kozo Hiraoka's skew gear calculations. I'm attaching the complete equation.
gbritnell

[zeeprogrammer]

Multiply the 1.7 * .844 first then add.

[stevehuckss396]

A = 21.82 + 2 * .85 * C0s(32.41) * 0.97674664063

A = 21.82 + 1.7 * Cos(32.41) * 0.97674664063

A = 21.82 + 1.435 * 0.97674664063

A = 21.82 + 1.401

A = 23.221

[steamer]

Ahhh Steve beat me too it....

[gbritnell]

Thanks guys,
It's great to have all the help. So all multiplication and division would be calculated before addition or subtraction?
gbritnell

[steamer]

The order is

Exponents and Roots
Multiplication and Division
Addition and Subtraction

Dave

[Tin Falcon]

Please Excuse My Dear Aunt sally
Parentheses, Exponents (and roots), Multiplication, division  Addition, subtraction
tin

[gbritnell]

Thanks Tin,
I went through all the calculations and their sample answers and they all came out correct. It's easy when you know how! I have been plugging my own numbers it but it's taking time. There's almost 3 pages of calculations to do.
Oh well, I have all winter to get this differential made.
gbritnell

[mklotz]

George,

If you're doing multiple calculations with the same formulae but different numbers, you may want to consider something like a programmable calculator or a spreadsheet. 

Once you've got the spreadsheet set up and operating correctly as proved by your sample calculations, plugging in your own numbers becomes a doodle and you're assured that no errors were made in the calculation (as is possible if done by a human).  Especially when doing design work, the ability to repeat calcs many times with slightly different numbers becomes a real time saver.

Moreover, if you ever do this again in the future, the spreadsheet implementation will remember perfectly how to do it - something most humans can't do.

[Jo]

Moreover, if you ever do this again in the future, the spreadsheet implementation will remember perfectly how to do it - something most humans can't do.

Or repeat exactly the same miss-calculation perfectly every time.

Jo

[mklotz]

Moreover, if you ever do this again in the future, the spreadsheet implementation will remember perfectly how to do it - something most humans can't do.

Or repeat exactly the same miss-calculation perfectly every time.

Jo

I guess you missed the part where I wrote,

"Once you've got the spreadsheet set up and operating correctly as proved by your sample calculations...."