You are Here: Home >< Maths

# Basic c2 graphs question Watch

1. Say you are given the equation y = x(x^2-1) to sketch the roots are (-1,0) (0,0) (1,0)

How would you sketch it I mean in terms of which side would you start of with how do you know where the max min points are.

Also does anybody know what the graph of y=-srt of x look like?
2. (Original post by IShouldBeRevising_)
Say you are given the equation y = x(x^2-1) to sketch the roots are (-1,0) (0,0) (1,0)

How would you sketch it I mean in terms of which side would you start of with how do you know where the max min points are.

Also does anybody know what the graph of y=-srt of x look like?
The graph of looks like this:

For the graph of,

You know the values where it crosses the x-axis, just consider all the regions, by subbing in some values to deduce the shape of the graph.

e.g. It crosses at (1,0), see what is the value of y when x=2, if it is positive then the graph will move upward and if it is negative, then the graph will move downwards.
3. (Original post by IShouldBeRevising_)
Say you are given the equation y = x(x^2-1) to sketch the roots are (-1,0) (0,0) (1,0)

How would you sketch it I mean in terms of which side would you start of with how do you know where the max min points are.

Also does anybody know what the graph of y=-srt of x look like?

Max/min occurs at stationary points where the gradient is equal to zero.

Differentiate the above expression, and set dy/dx=0 to find the stationary points. Find the 2nd derivative to check whether the points are max or min.
4. (Original post by raheem94)

Max/min occurs at stationary points where the gradient is equal to zero.

Differentiate the above expression, and set dy/dx=0 to find the stationary points. Find the 2nd derivative to check whether the points are max or min.

(Original post by raheem94)
The graph of looks like this:

For the graph of,

You know the values where it crosses the x-axis, just consider all the regions, by subbing in some values to deduce the shape of the graph.

e.g. It crosses at (1,0), see what is the value of y when x=2, if it is positive then the graph will move upward and if it is negative, then the graph will move downwards.
Thanks well explained... I get it now

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: May 5, 2012
Today on TSR

### 8 things that will happen during Freshers

Don't say we didn't warn you...

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