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how to find range/ domain C3 PLEASE HELP

I am soo stuck. I always learn it but forget it. Can somebody please help me.

I know range is the output, and domain the input.

Is there any 'cheat' I can do?

Reply 1

Heeere's Johnny!

do you mean a way of remembering what the 2 are?

d comes before r in the alphabet? so domain is the numbers you put in, and range is what you get out??

Reply 2

games211

Original post by Heeere's Johnny!

do you mean a way of remembering what the 2 are?

d comes before r in the alphabet? so domain is the numbers you put in, and range is what you get out??

Sorry I meant how to apply that to a question I.e

F(x)= 1/x+1 where x>3

Find range? :confused:

Reply 3

Mathsz0r

Original post by games211

Sorry I meant how to apply that to a question I.e

F(x)= 1/x+1 where x>3

Find range? :confused:

Just substitute x=3 in which would be f(x)=1/4. Therefore the range of f(x) is <1/4.

Reply 4

games211

Original post by Mathsz0r

Just substitute x=3 in which would be f(x)=1/4. Therefore the range of f(x) is <1/4.

but why is the sign <1/4

Reply 5

Mathsz0r

Original post by games211

but why is the sign <1/4

If the x values are x>3, 1/1+x is going to be a decreasing value. Try it - substitute in x=4,x=5 etc. It'll eventually converge to 0 for x tending towards infinity.