For instance, consider a
function y = f(x).
_____________
x | y
------------------
1 | -3
3 | 0
4 | 30
6 | 132
------------------
Now I need to find the value of y for x=5
Can I solve this using my fx-991 ES, if yes please tell me how
Thanks in advance

Fx-991es How To Calculate Interpolation
Started by
enakta13
, Dec 26 2011 03:08 PM
4 replies to this topic
#1
Posted 26 December 2011 - 03:08 PM
#2
Posted 12 January 2012 - 04:36 AM
Well you say you have a function: y = f(x).
But then you present a table:
_____________
x | y
------------------
1 | -3
3 | 0
4 | 30
6 | 132
------------------
This is not a function.
To find the value for x=5 you have to either determine the function first and then just calculate it for x=5, the problem being, there are many possible functions that will yield that table;
or linearly interpolate between 4 and 6, x=5 resulting in y=81, via:
Let x1 be the x-value smaller than your x (here,4); x2 the x-value larger than your x (here,6); y1 and y2 the corresponding y-values (here, 30 and 132); then
y = y1+(x-x1)/(x2-x1)*(y2-y1) = 30+(5-4)/(6-4)*(132-30) = 30+1/2*102= 30+51 = 81.
But then you present a table:
_____________
x | y
------------------
1 | -3
3 | 0
4 | 30
6 | 132
------------------
This is not a function.
To find the value for x=5 you have to either determine the function first and then just calculate it for x=5, the problem being, there are many possible functions that will yield that table;
or linearly interpolate between 4 and 6, x=5 resulting in y=81, via:
Let x1 be the x-value smaller than your x (here,4); x2 the x-value larger than your x (here,6); y1 and y2 the corresponding y-values (here, 30 and 132); then
y = y1+(x-x1)/(x2-x1)*(y2-y1) = 30+(5-4)/(6-4)*(132-30) = 30+1/2*102= 30+51 = 81.
#3
Posted 12 January 2012 - 02:55 PM
For instance, consider a
function y = f(x).
_____________
x | y
------------------
1 | -3
3 | 0
4 | 30
6 | 132
------------------
Now I need to find the value of y for x=5
Can I solve this using my fx-991 ES, if yes please tell me how
Thanks in advance
I think perhaps it only supports quadratic regression, a cubic regression seemed like pretty fair approximation (in fact the formula looks a bit text-book-like).
f(5) = -0.5x^3 + 13.5x^2 - 46x + 30 = 75
With quadratic regression I get f(5) = 72 (with messier numbers in the formula).
#4
Posted 20 October 2013 - 07:45 AM
Yes you can do it just follow this instruction:Its simple
press mode
3;stat
2;A+Bx
l x l y l
l 2 l 4.6 l
l 4 l 5.9 l
press; AC
press;5.9
press; shift
press;1
press;7 (reg)
press;5 (comma)
press;=
u will get ans
source:
http://www.fixya.com...polate_in_casio
press mode
3;stat
2;A+Bx
l x l y l
l 2 l 4.6 l
l 4 l 5.9 l
press; AC
press;5.9
press; shift
press;1
press;7 (reg)
press;5 (comma)
press;=
u will get ans
source:
http://www.fixya.com...polate_in_casio
#5
Posted 31 October 2013 - 11:31 PM
@ Verena
He didn't say he has a function y = f(x) ; he said to "consider" a function... That means the table presented contains the data that describes the unknown function f(x) to derive.
He didn't say he has a function y = f(x) ; he said to "consider" a function... That means the table presented contains the data that describes the unknown function f(x) to derive.
2 user(s) are reading this topic
0 members, 2 guests, 0 anonymous users