help w/ math prob

efript

Senior member
Aug 17, 2002
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problem: the table below contains values of the functions p and q. construct a table of values for r(x)=p(q(x))

then the table:

x 0 1 2 3 4 5
p(x) 1 0 5 2 3 4
q(x) 5 2 3 1 4 8


i dont understand what im supposed to do.... fvck precal.... please help thanks guys

 

dighn

Lifer
Aug 12, 2001
22,820
4
81
Originally posted by: efript
problem: the table below contains values of the functions p and q. construct a table of values for r(x)=p(q(x))

then the table:

x 0 1 2 3 4 5
p(x) 1 0 5 2 3 4
q(x) 5 2 3 1 4 8


i dont understand what im supposed to do.... fvck precal.... please help thanks guys

p and q are functions, and their results are "calculated" for you
eg q(2) is 3, then p(q(2)) = p(3) = 2
 

Broohaha

Banned
Jan 4, 2001
3,973
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that's PRECALC??? wtF? i'm a senior in college and i have no clue what dat sh!t means.

then again im a humanities major so screw it :)
 

efript

Senior member
Aug 17, 2002
316
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0
ok but it says for me to construct a table for the values of r(x)=p(q(x))

what does that mean?
 

dighn

Lifer
Aug 12, 2001
22,820
4
81
Originally posted by: efript
ok but it says for me to construct a table for the values of r(x)=p(q(x))

what does that mean?

i'm thinking something like:
x: 0 1 2 3 4 5
r(x): blah blah like p and q
 

KEV1N

Platinum Member
Jan 15, 2000
2,932
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p(0) = 1
p(1) = 0

p(2) = 5
p(3) = 2
p(4) = 3
p(5) = 4

If you graph this out, you can't really figure out a simple function for p(x). So, you'll have to split the domain into sections.

For x from 0 to 1, p(x) = -x + 1
For x from 1 to 2, p(x) = 5(x-1)
For x from 2 to 3, p(x) .....
......

Therefore I think it's impossible to do this problem unless you specify domains for each function. After doing that for each section of the domain for both p(x) and q(x), fond the composite. Wow, this is pretty complicated for Precal. I did this for Abstract Math my 3rd year of college.
 

efript

Senior member
Aug 17, 2002
316
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umm its possible... she gave it to us for hw she wouldnt give us something we couldnt do
 

KEV1N

Platinum Member
Jan 15, 2000
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Originally posted by: efript
umm its possible... she gave it to us for hw she wouldnt give us something we couldnt do

I meant it is impossible unless you break up the domain. Maybe I'm overthinking the problem.
 

dighn

Lifer
Aug 12, 2001
22,820
4
81
Originally posted by: KEV1N
p(0) = 1
p(1) = 0


Therefore I think it's impossible to do this problem unless you specify domains for each function. After doing that for each section of the domain for both p(x) and q(x), fond the composite. Wow, this is pretty complicated for Precal. I did this for Abstract Math my 3rd year of college.

I think you are making it more complicated than it is

the question says
problem: the table below contains values of the functions p and q. construct a table of values for r(x)=p(q(x))

then the table:

x 0 1 2 3 4 5
p(x) 1 0 5 2 3 4
q(x) 5 2 3 1 4 8

I'm pretty sure it's asking the same kind of table the p/q function answers are given in and that can be calculated simply from that table.
 

RossGr

Diamond Member
Jan 11, 2000
3,383
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Originally posted by: KEV1N
p(0) = 1
p(1) = 0

p(2) = 5
p(3) = 2
p(4) = 3
p(5) = 4

If you graph this out, you can't really figure out a simple function for p(x). So, you'll have to split the domain into sections.


Lets start from here, now take your values for q
x 0 1 2 3 4 5
p(x) 1 0 5 2 3 4
q(x) 5 2 3 1 4 8

I interpt this to mean

q(0)=5
q(1)=2
q(2)=3
q(3)=1
etc

now r(x)= p(q(x))
so r(0)=p(q(0)=p(5)=4
r(1)=p(q(1))=p(2)=5

Can you finish?