7 replies to this topic

[buz260]

Hi if you could help me that'd be great. Firstly how can i configure it so that irrational numbers are displayed as fractions with roots etc... eg cos30 = root3/2. The lesser casio calculators can do this, so surely my new graphical one can too??
Also how can i get the modulus function on my calculator (ie how could i type eg. |x|)?
Thanks - got an exam tomorrow (a level maths) so would really appreciate a fast response. Cheers

[TyYann]

To get answers like cos30 = root3/2 on a calculator, you need a CAS calculator. fx 9860 is not CAS...

There is no modulus modulo function on this calc either. You need to do it manually (eg : divide by the modulus and find the remain of the division).

I wrote this program for you :

"A Mod B: A"?->A
"B"?->B
A-Int (A/B)xB->C
If C<0
Then C+B->C
IfEnd

Where
-> is
/ is

Hope this helps.

EDIT : Change Modulus to modulo. I misunderstood, sorry.

[caspro]

By modulus, he means |x| i.e. Abs X (not modulo)

Abs is on optn f6 f4 f1 or from the catalog

and no the 9860 does not have exact values for trig functions built-in.

[buz260]

Thanks v. much for all the help - have found modulus function thanks to caspro. You said it doesnt have the exact values "built in" - is there a way of putting something on it so exact values are displayed?

[TyYann]

By modulus, he means |x| i.e. Abs X (not modulo)

Pardon my French...

[buz260]

any other suggestions.... - exams in less than 24 hours

[caspro]

If you don't want to memorise the exact values then here is a method to
work them out.

Type cos 30 or whatever ( make sure the calc is in deg mode first )

You get the answer 0.866025....

Now all the exact values involve square roots and 1/sqrts
(except for easy results like 0 or 0.5 which don't need any further simplification)

So just square the result and see what you get.


e.g. 0.866....^2 = 0.75 which is clearly 3/4 which means the answer was =sqrt (3/4) which simplifies to = (sqrt 3)/2

another example:

tan 30=0.57735..... squaring gives 0.333..... i.e. 1/3 so answer was sqrt (1/3) = 1/sqrt 3

[buz260]

good idea - thanks... i think i almost know them now anyway after thinking about them so much!
Thanks 4 all the help