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Maths help inverse functions.

https://www.youtube.com/watch?v=z9cZtBXS4z4

This question is doing my head in, and I keep getting answer choice E which is incorrect. I am getting the wrong function. Would apprecitate any advice.

Thanks.
I'm trying to self teach C3 over the summer so might be wrong, but I don't understand how it could be E?
If it was E the minimum point would be (-4,3) but clearly we have a positive x-coordinate? So it can't be that
I got C after the process of elimination :tongue:

My reasoning:
It can't be A because it would cross the y-axis at (0,-1) which it doesn't look like it does
Not B as that would just be a parabola shifted 11 units
Not D as you would have a negative x coordinate for minimum but it looks positive
Not E because it has a negative x coordinate and it doesn't seem to be shifted 3 units up

So C
(edited 9 years ago)
Reply 2
Avatar for cdude
cdude
18
When are you going to use this in future life?
Reply 3
Avatar for EmmaBxoxo
EmmaBxoxo
OP
19
Original post by Super199
I'm trying to self teach C3 over the summer so might be wrong, but I don't understand how it could be E?
If it was E the minimum point would be (-4,3) but clearly we have a positive x-coordinate? So it can't be that
I got C after the process of elimination :tongue:

My reasoning:
It can't be A because it would cross the y-axis at (0,-1) which it doesn't look like it does
Not B as that would just be a parabola shifted 11 units
Not D as you would have a negative x coordinate for minimum but it looks positive
Not E because it has a negative x coordinate and it doesn't seem to be shifted 3 units up

So C


See I ruled out A and B because choices C,D and E look more similar hence little difference will give the points.

The thing is I don't get is the equation is in terms of x and not y, does this affect anything. The inverse would mean that the circled point would be in either of the left quadrants so I assumed that from that it would be D or E - this is obviously wrong.

The question says that the graph represesnts the function f(x) and so surely the inverse cannot be the same as f(x) - perhaps this is my mistake.

Original post by cdude
When are you going to use this in future life?


I'm more concerned about getting these questions right for the test :tongue:
Original post by EmmaBxoxo
See I ruled out A and B because choices C,D and E look more similar hence little difference will give the points.

The thing is I don't get is the equation is in terms of x and not y, does this affect anything. The inverse would mean that the circled point would be in either of the left quadrants so I assumed that from that it would be D or E - this is obviously wrong.

The question says that the graph represesnts the function f(x) and so surely the inverse cannot be the same as f(x) - perhaps this is my mistake.


Mm I'm not too sure, I only started doing this topic yesterday. But best of luck with your test :smile:
Original post by cdude
When are you going to use this in future life?


Are you dissing maths?
Reply 6
Avatar for cdude
cdude
18
Original post by rayquaza17
Are you dissing maths?


Not 'dissing' it, no.

Just questioning why we get taught this stuff we're never going to use
Original post by cdude
Not 'dissing' it, no.

Just questioning why we get taught this stuff we're never going to use


I suppose everyone is entitled to their opinions.
Reply 8
Avatar for EmmaBxoxo
EmmaBxoxo
OP
19
Original post by Super199
Mm I'm not too sure, I only started doing this topic yesterday. But best of luck with your test :smile:



Thanks for your help, and thanks again :smile:

Only TSR revises during summer lmao, good luck with your core 3, I did that exam recently :smile:
Original post by cdude
Not 'dissing' it, no.

Just questioning why we get taught this stuff we're never going to use

someone sucks at maths
Reply 10
Avatar for cdude
cdude
18
Original post by Mike_123
someone sucks at maths



No, i just put minimal effort in. I knew i would never use 80% of the stuff i learnt

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