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Math's doubts
#1
Posted 03 November 2003 - 01:36 AM
Today i had this one, hope that someone can understand & help me:
I have this math expression:
1 + a + a^2 + a^3 + .... (it spreads to infinite, n)
I want to re-write this via classpad (i want to apply this for exams), my teacher give us this result:
1 - a^(n+1)
1 - a
Does some classpad command do that?
#2
Posted 03 November 2003 - 02:10 PM
Procedure:
Press KeyBoard, 2D, then find the symbol for sum (upcase sigma)
In the lower box, tap x. Next, tap 1 to the right box.
Next, In the top box, input n.
In the last box, input a^x
After that, tap everywhere out of Sigma symbol and tap + 1.
Press EXE.
To get the same result with your teacher, select Action, Transformation, Combine, and tap ans, EXE. You will get the same result.
GoodLuck
![:)](/dot/public/style_emoticons/default/smile.png)
Oh, what grade are you in?
#3
Posted 03 November 2003 - 10:16 PM
Right now I'm studing the 7th of 8 semester of electronic engineer.
#4
Posted 04 November 2003 - 02:01 AM
As I say above, In the lower box of Sigma symbol, you change x=1 to x=0.
Then, you dont need to +1 because a^0=1 with all a<>0. Then press EXE and you will go directly to the result.
![:thumbsup:](/dot/public/style_emoticons/default/thumbs_up.gif)
#5
Posted 04 November 2003 - 06:45 AM
![:)](/dot/public/style_emoticons/default/smile.png)
#6
Posted 26 November 2003 - 04:48 AM
"The ModBox for represent statics variables (one dimension) dont work; its a method for determinate "outliers", but it really do the same graphic that the "box and whiskers" option."
I hope somebody can help him (i dont know and i dont like anything about statics
![:P](/dot/public/style_emoticons/default/tongue.png)
#7
Posted 30 November 2003 - 05:14 PM
y=sin(x)|x=int(x)
This work well in the classpad manager, but in the classpad no
![:unsure:](/dot/public/style_emoticons/default/unsure.png)
Try this and let me know what happend...
#8
Posted 01 December 2003 - 01:42 AM
I tried the code you write, both ClassPad and the manager produced the same result: the graph window appear some dot. What did the graph window appear on your ClassPad?
Oh, could someone help me to solve: (sin(3x/2))^2=sin(x)sin(3x).
![:rolleyes:](/dot/public/style_emoticons/default/rolleyes.gif)
#9
Posted 01 December 2003 - 05:20 AM
![:rolleyes:](/dot/public/style_emoticons/default/rolleyes.gif)
Strange, other guy had the same error that me.
#10
Posted 01 December 2003 - 09:02 AM
Well,Oh, could someone help me to solve: (sin(3x/2))^2=sin(x)sin(3x).
'x=0+2k*pi' is one obvious solution
-- EDIT --
Solutions:
x = 2k*pi
x = 2/3 * pi + 2k*pi
x = pi/6 - 4/3 * pi + 2k*pi
x = -pi/6 + 4/3 * pi + 2k*pi
#11
Posted 02 December 2003 - 02:35 AM
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