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Maths question help please

Hi, please could I have some help on question 8ii a below. I’m confused on how to find the range. I thought there would be an asymptote at 0 but that’s not the case. Any advice on how to work it out?
Question: https://ibb.co/67WsP766
Thanks!

Reply 1

Original post
by anonymous56754
Hi, please could I have some help on question 8ii a below. I’m confused on how to find the range. I thought there would be an asymptote at 0 but that’s not the case. Any advice on how to work it out?
Question: https://ibb.co/67WsP766
Thanks!

Have you sketched it correctly? If so the min and max (range) should be simply given by the previous part and a simple spot?

Reply 2

Original post
by anonymous56754
Hi, please could I have some help on question 8ii a below. I’m confused on how to find the range. I thought there would be an asymptote at 0 but that’s not the case. Any advice on how to work it out?
Question: https://ibb.co/67WsP766
Thanks!

when g(x) =|2x+4/x2+5|, the part of the graph below the x-axis (the -ve y values of the graph) will be reflected in the x-axis such that all y-values are positive.

u can draw out this graph and find the range of g

Reply 3

I sketched it and it and I understand the max should be 1 but I'm unsure why the min is zero when the graph doesn't touch the x axis? Thanks

Reply 4

Original post
by anonymous56754
I sketched it and it and I understand the max should be 1 but I'm unsure why the min is zero when the graph doesn't touch the x axis? Thanks

the range shld look like this, (0,1]. ( ) means the range is not inclusive of wtv value is in there. in this case, not inclusive of 0 as there is an asymptote of x=0. [ ] means inclusive of the value, meaning inclusive of 1

Reply 5

Original post
by helloos
the range shld look like this, (0,1]. ( ) means the range is not inclusive of wtv value is in there. in this case, not inclusive of 0 as there is an asymptote of x=0. [ ] means inclusive of the value, meaning inclusive of 1

but the markscheme says it is inclusive
'State values between 0 and their y-value of maximum point lying in first quadrant M1 accept or < signs here State correct 0 1 y A1ft following their y-value of maximum point in first quadrant; now with signs; or equiv perhaps involving g or g( )'

Reply 6

Original post
by anonymous56754
but the markscheme says it is inclusive
'State values between 0 and their y-value of maximum point lying in first quadrant M1 accept or < signs here State correct 0 1 y A1ft following their y-value of maximum point in first quadrant; now with signs; or equiv perhaps involving g or g( )'

The range shoud be [0,1]. When x=-2
g(-2) = f(-2) = 0
as |0| = 0. g() touches the x-axis at that point whereas f() crosses the x-axis at that point. Just think about the graph of |x| and what happens when x=0.
(edited 10 months ago)

Reply 7

Original post
by mqb2766
The range shoud be [0,1]. When x=-1/2
g(-1/2) = f(-1/2) = 0
as |0| = 0. g() touches the x-axis at that point whereas f() crosses the x-axis at that point. Just think about the graph of |x| and what happens when x=0.

Oh ok thanks!

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