Domain and range c3 question

hi, I would like some help with Q6b and Q6c please. Since x >1 surely the biggest y value can only be 4/3 so for the range I got 0<f x <4/3 but the answer is x can't be 0 why ???

Cheers

Reply 1

NotNotBatman

Original post by coconut64

hi, I would like some help with Q6b and Q6c please. Since x >1 surely the biggest y value can only be 4/3 so for the range I got 0<f x <4/3 but the answer is x can't be 0 why ???

Cheers

Draw the graph, as x gets larger f(x) gets smaller, it tends to 0, but the fraction cannot equal 0, so there is an asymptote at y=0

(edited 7 years ago)

Reply 2

coconut64

Original post by NotNotBatman

Draw the graph, as x gets larger f(x) gets smaller, it tends to 0, but the fraction cannot equal 0, so there is an asymptote at x=0

Isnt the x asymptote at x=-1/2? Since it shifts to left by 1 then halved . ... The graph I drew indicates that all the y values can only be 4/3 to 0 as x>1. Thanks

Reply 3

NotNotBatman

Original post by coconut64

Isnt the x asymptote at x=-1/2? Since it shifts to left by 1 then halved . ... The graph I drew indicates that all the y values can only be 4/3 to 0 as x>1. Thanks

Sorry, I meant at y=0 , and the range of y values is less than 4/3 and greater than 0, so you've got it right.

Reply 4

the bear

to draw y = 4/ { 2x + 1 }

i) draw y = 1/x : you should know what this looks like.

ii) move it 1 unit left

iii) squash horizontally by a factor of 2

iv) stretch vertically by a factor of 4

:hat2: