Spreadsheet problem with entering complex equations

abadger shared this question 9 years ago
Answered

Any advice on how to enter longish equation into spreadsheet. It seems to freeze the spreadsheet or get syntax errors that don't seem to be there ?


For instance, I wish to calculate speed to throw a basketball ..given the angle...distance to basket and height to basket. The equation for this speed from SUVAT equations comes down to:-


speed = sqrt((4.9d^2)/((d * tan(theta] - h) cos^2(theta)))


theta is angle ... can vary from say 30 to 80 degrees. I realise you need a little o above angle when using trig functions.

d is horizontal distance to basket = 3

h is height to basket = 1


I just cannot enter this equation into geogebra spreadsheet without above errors occurring...sometimes when trying to re-edit equation you get a pop-up and sometimes not. Sometimes it comes back with an = ... in the box, like it is now not being treated as an equation.


I can do this fairly easily in google docs ... any advice welcome. ?


Dave

Comments (5)

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Maybe it's just a matter of parentheses...

have a look here:

speed = sqrt( (4.9d^2) / ( (d * tan(Θ)-h)* (cos(Θ))^2 ) )

it should work (I've left some blanks between parentheses to show the nesting).

You used a ] which hasn't a corresponding [

Also, use the syntax (cos(theta))^n to raise the cosine function to power n or use Alt-2 to square.

If you just type cos^2(theta) it doesn't work.


Try and let us know...

Ciao,

S.

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I have an off-topic question if you don't mind: why does writing in some spreadsheet cell =3*A2

, for example, get me 3A2 in the cell instead of doing the expected multiplication of 3 by the value of cell A2?

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Thanks for reply.


Have succeeded with your advice...but if you look at attached file, and try to edit equation in cells A1 and A3 it seems very unresponsive. Or is this just my computer..running GG 4.0.4. Still feel something is slow / buggy here as it seems far harder to get this working than on other spreadsheets.


Thx Dave


ps Now know it's "Alt T" to get theta symbol !

https://ggbm.at/551599

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This is my idea for your worksheet.

(The worksheet must be active)

Create three sliders: Θ (angle), d and h, with suitable ranges.

Input your "speed" calculation, then right click on its name in the Algebra View and select "Trace on the spreadsheet" option in the properties popup dialog.

If you accept defaults for tracing, the first column of your worksheet will have the label "speed".

Try to move the angle slider: the corresponding values for speed will appear in the worksheet.

Now that you know howto, you can adjust your tracing as you wish.

:wink:

(btw I had no problems with your worksheet.)

GeoGebra Keyboard Shortcuts


Ciao,

S.

https://ggbm.at/551609

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Thanks for the reply....am getting there with this.


Does seem to be better now, maybe 4.0.6 is also helping here.


Not used the record to spreadsheet before, the idea for the students is to plot speed against angle to see the best angle to score with the 'softest' throw. Look at graphics 2 view in attached to see this.


My graphics 1 view is the visualisation of the moving ball ...more for fun and testing the solutions do work.


Again - thank you, Dave

https://ggbm.at/551621

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