You are Here: Home >< A-levels

how to find a range of a function? watch

1. given that the domain of each function is 0 equal or smaller than x equal or smaller than 6 for x belongs to R, how to find the range of:

a) f(x)=12/x+2

b) g(x)=(x-2)^2

any help would be appreciated!
2. (Original post by jianwen)
given that the domain of each function is 0 equal or smaller than x equal or smaller than 6 for x belongs to R, how to find the range of:

a) f(x)=12/x+2

b) g(x)=(x-2)^2

any help would be appreciated!

Think about what a sketch of the function would look like for the domain (the values of x given) - the range is the values on the 'y' axis.
3. (Original post by jianwen)
given that the domain of each function is 0 equal or smaller than x equal or smaller than 6 for x belongs to R, how to find the range of:

a) f(x)=12/x+2

b) g(x)=(x-2)^2

any help would be appreciated!
The range is like 'okay, the output will always be bigger than this number... or smaller than this number... or both'.

It often helps to draw the graph and or test the limits of the domain.
4. (Original post by jianwen)
given that the domain of each function is 0 equal or smaller than x equal or smaller than 6 for x belongs to R, how to find the range of:

a) f(x)=12/x+2

b) g(x)=(x-2)^2

any help would be appreciated!
Well, the range is basically the set of values that the function spits out once you feed every number from the domain into it.

For (a) if you were to feed the function the set into the function, what set of numbers would the function spit out?

Same goes for (b).

MAJOR HINT:
Spoiler:
Show
(a) is a decreasing function over its domain. The value of its endpoints are and
5. When trying to find the range, always sketch the graph. Look above and below and notice the y-values. That's your range. Don't know if this was helpful lol I'm doing this chapter as well
6. y value is the range and x is the domain (I used to remember it as x the man aka xdomain) . So you sub in x into those equation to find range.

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: September 15, 2015
Today on TSR

He broke up with me because of long distance

Now I'm moving to his city

University open days

1. Norwich University of the Arts
Thu, 19 Jul '18
2. University of Sunderland
Thu, 19 Jul '18
3. Plymouth College of Art
Thu, 19 Jul '18
Poll

All the essentials

Student life: what to expect

What it's really like going to uni

Essay expert

Learn to write like a pro with our ultimate essay guide.

Create a study plan

Get your head around what you need to do and when with the study planner tool.

Resources by subject

Everything from mind maps to class notes.

Study tips from A* students

Students who got top grades in their A-levels share their secrets

Groups associated with this forum:

View associated groups

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