You are Here: Home >< Maths

# Graphs. :) Watch

1. Hello there,

Given that f(x) = e^x, sketch, on the same diagram the graphs of y = f(x) and y = 2f(x) - 3. I know the graph of e^x, for the second graph would I move this graph 3 up and then double the y axis?

Also I have been asked to sketch the graph of y = f^-1 (x) and y = f(x). [NOT RELATED TO QUESTION ABOVE]. Do I basically sub in numbers for x and get the y values, and then plot the graph for y = f^-1? Is there any relationship (graph wise) with a function and inverse function? Or do I sub in numbers for x etc again and plot that?

Thank you very much everyone.
2. (Original post by apo1324)
Hello there,

Given that f(x) = e^x, sketch, on the same diagram the graphs of y = f(x) and y = 2f(x) - 3. I know the graph of e^x, for the second graph would I move this graph 3 up and then double the y axis?

Also I have been asked to sketch the graph of y = f^-1 (x) and y = f(x). [NOT RELATED TO QUESTION ABOVE]. Do I basically sub in numbers for x and get the y values, and then plot the graph for y = f^-1? Is there any relationship (graph wise) with a function and inverse function? Or do I sub in numbers for x etc again and plot that?

Thank you very much everyone.
For 2f(x)-3, yes you would stretch it by scale factor 2 parallel to they y axis, though think about -3 at the end would this move every value up 3 or down 3.

b) is there a function defined for f(x) in b?
3. (Original post by 2^1/2)
For 2f(x)-3, yes you would stretch it by scale factor 2 parallel to they y axis, though think about -3 at the end would this move every value up 3 or down 3.

b) is there a function defined for f(x) in b?
Yeah. They want me to sketch 1/2(sqrt)x-3 and sketch the inverse of it. Also I just realised it would be 3 down for the first question.
4. (Original post by apo1324)
Yeah. They want me to sketch 1/2(sqrt)x-3 and sketch the inverse of it. Also I just realised it would be 3 down for the first question.

yep, cool

for part b, was just thinking if f^-1(x)=y then f(y)=x will be the same graph
so for any function the inverse is the graph reflected in the line y=x

that may help or you could just sub numbers in
5. (Original post by 2^1/2)
yep, cool

for part b, was just thinking if f^-1(x)=y then f(y)=x that may help or you could just sub numbers in but that isn't a simple function
Ahhh, thank you very much for your time!
6. (Original post by apo1324)
Ahhh, thank you very much for your time!
that's ok, sorry i spent a while editing my last post

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: November 30, 2010
Today on TSR

### Degrees to get rich!

... and the ones that won't

### Women equal with Men?

Discussions on TSR

• Latest
• ## See more of what you like on The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

• Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams

## Groups associated with this forum:

View associated groups
Discussions on TSR

• Latest
• ## See more of what you like on The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

• The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.