Sidebar Sidebar
Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

need help with my math hw lol

G

GD0X

Guest
Original poster
Mar 20, 2011
97
0
1. f(x)=4/(4x-3) what does f^-y equal?

2. h(x)=3-(x+5/x-7) what is h(9)^-1?

3. f(x)=x-1/x^2+1
g(x)=x+10/x+13

What is (f o g)(x)?
and what is
What is (g o f)(x)?

4. h(x)=square root of (1/x^2+7) + 16

if f(x)=square root of x, then find a function g such that h=f o g

if f(x)=square root of x+16, then find a function g such that h=f o g.


Don't have any resources available at the moment, but need some help haha.
 
1. f(x)=4/(4x-3) what does f^-y equal?

2. h(x)=3-(x+5/x-7) what is h(9)^-1?

3. f(x)=x-1/x^2+1
g(x)=x+10/x+13

What is (f o g)(x)?
and what is
What is (g o f)(x)?

4. h(x)=square root of (1/x^2+7) + 16

if f(x)=square root of x, then find a function g such that h=f o g

if f(x)=square root of x+16, then find a function g such that h=f o g.


Don't have any resources available at the moment, but need some help haha.
Click to expand...

This might help:

http://math.aa.psu.edu/~mark/Math22/combine.pdf
 
ender land said:
That's what I though initially but the first example makes no sense. Unless it was supposed to be


1. f(x)=4/(4x-3) what does f(y)^-1 equal?
Click to expand...
I honestly have no idea about 1, but it makes sense for 2, surely? (I know, I just set up a joke there).
 
A vendor seeking extra help for nonsensical Pre-Calc functions?
I have a strange and creeping doubt that this may be, in fact, an advertisement for the Sylvan Learning® Center.
 
GD0X said:
1. f(x)=4/(4x-3) what does f^-y equal?

2. h(x)=3-(x+5/x-7) what is h(9)^-1?

3. f(x)=x-1/x^2+1
g(x)=x+10/x+13

What is (f o g)(x)?
and what is
What is (g o f)(x)?

4. h(x)=square root of (1/x^2+7) + 16

if f(x)=square root of x, then find a function g such that h=f o g

if f(x)=square root of x+16, then find a function g such that h=f o g.


Don't have any resources available at the moment, but need some help haha.
Click to expand...

#1 Not sure what it's asking. I'd just solve for x instead of y. So set the equation to "x="
#2 Not sure what it's asking again, but I'd plug 9 in and then find the inverse of the equation, basically like #1.
#3 You basically plug the equations into the each other.
(f o g)(x)= g(f(x)) (plug equation F into G)
(g o f)(x) = f(g(x)) (plug equation G into F)

Isn't precalulus all about trigonometry? This is Algebra, no?
I know my trigonmetry very well. QUICK : 3π/4 :p
 
visim91 said:
A vendor seeking extra help for nonsensical Pre-Calc functions?
I have a strange and creeping doubt that this may be, in fact, an advertisement for the Sylvan Learning® Center.
Click to expand...

no no. I just have website haha

----------

i know mostly how do it, but i still need helping actually getting to the answer.
 
wordoflife said:
#1 Not sure what it's asking. I'd just solve for x instead of y. So set the equation to "x="
#2 Not sure what it's asking again, but I'd plug 9 in and then find the inverse of the equation, basically like #1.
#3 You basically plug the equations into the each other.
(f o g)(x)= g(f(x)) (plug equation F into G)
(g o f)(x) = f(g(x)) (plug equation G into F)

Isn't precalulus all about trigonometry? This is Algebra, no?
I know my trigonmetry very well. QUICK : 3π/4 :p
Click to expand...

Yeah, it has to be Pre-Cal Trig..
 
GD0X said:
1. f(x)=4/(4x-3) what does f^-y equal?
Inverse, is what I presume it's asking. Switch y and x, solve for y, switch your y into f^-1(x)
2. h(x)=3-(x+5/x-7) what is h(9)^-1?

Same as number 1, except once you get your equation, plug in 9 into every x

3. f(x)=x-1/x^2+1
g(x)=x+10/x+13

What is (f o g)(x)?
Take g(x), and plug it into every x in f(x). So it'll be (x+10/x+13)-1/(x+10/x+13)^2+1
and what is
What is (g o f)(x)?

Same as part 1, except other way around. Take f(x) and plug it into every x in g(x)
4. h(x)=square root of (1/x^2+7) + 16

if f(x)=square root of x, then find a function g such that h=f o g

if f(x)=square root of x+16, then find a function g such that h=f o g.


Don't have any resources available at the moment, but need some help haha.
Click to expand...


Easy enough.


I don't feel like continuing...it's the same stuff.
 
WolframAlpha is your friend. It will even show you the stages to solve each problem...
 
I'd love if there was a math book that explained real world uses for all that stuff. I'd buy it in a heart beat! (Seriously I would).

A lot of math I thought would be useless pops up in video game programming (I can't tell you how often sine and cosine waves came in handy, or trig, or even some discrete math) but even when I go back and study math to brush up on my skills I get lost because nothing ever explains a real world purpose for certain types of math.

Sorry didn't mean to hijack ;)
 
chrono1081 said:
I'd love if there was a math book that explained real world uses for all that stuff. I'd buy it in a heart beat! (Seriously I would).

A lot of math I thought would be useless pops up in video game programming (I can't tell you how often sine and cosine waves came in handy, or trig, or even some discrete math) but even when I go back and study math to brush up on my skills I get lost because nothing ever explains a real world purpose for certain types of math.

Sorry didn't mean to hijack ;)
Click to expand...

Basic functions like these are useful in lots of fields, or rather one must understand the fundamentals before grasping the more sophisticated elements that a particular profession will use.

That said, OP you need to learn how to do this, not try to get easy answers. Filling in an easy answer will get you a rubber stamp today but an obstacle tomorrow. Ask us what you don't understand, don't expect us to think for you.
 
You must log in or register to reply here.
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.
Top Bottom
Back