domain and range of function (1 Viewer)

[maths lover]

another domain and function question just having troubles sketching it cause i dnt know what is it supposed to look like. X^2-2X+Y^2-4Y+1=0

 

[Mature Lamb]

another domain and function question just having troubles sketching it cause i dnt know what is it supposed to look like. X^2-2X+Y^2-4Y+1=0

complete the square in x and y and then try again

 

[maths lover]

I got no where

 

[SpiralFlex]

Remember sketching the function will help.

Complete the square:





As you can see it is a circle. There is a centre at (1, 2) with radius 2.

Sketch it, so the X coordinate is 1, 2 units either side of it, so

Domain:

Y coordinate is 2, 2 units above and below it.

Range:

 

[maths lover]

were did u get the four from

 

[SpiralFlex]

were did u get the four from

I added 4 to one side to complete the square, I have to add it on the other side too. It balances it out.

 

[maths lover]

oh ok thanks

 

[SpiralFlex]

oh ok thanks

No worries, always sketch the graph and you will be able to see what x and y values can hold.

 

[maths lover]

so how do u go about questions such as this one when there is no clear relationship with the general forms of graphs.

 

[SpiralFlex]

so how do u go about questions such as this one when there is no clear relationship with the general forms of graphs.

Practise. You must ask yourself, where are the x values restricted? And where are the y values restricted? Once you do a fair bit of work on domain and range questions, you shall be brilliant at it.

 

[annagurl]

eww, math