General Certificate of Tertiary Education

[sly elk]

explain pls

[pale tangle]

,rotate

[pale tangle]

@sly elk

[quick turret]

i do it like this

am i fried?

i imagine plotting actual values

[pale tangle]

Yea

[quick turret]

really

[pale tangle]

Yea it's reflection cuz see

[quick turret]

.rotate

,rotate

[quick turret]

ok but

whats stopping me from

using values

this is y = 0.5^-x
the top one is y = 0.5^x

[pale tangle]

Time consuming

[quick turret]

so how does

knowing its a reflection

help u draw it..

[pale tangle]

Ik what the graph of 2^x looks like

So I just reflect that in the y axis

[quick turret]

2^x is like the 2nd one

right

[pale tangle]

Yea

[quick turret]

so u draw the inverse

oh

[pale tangle]

Not inverse

[quick turret]

y axis

[pale tangle]

Inverse is a reflection in the like y = x

[quick turret]

the line never touches the x axis

[pale tangle]

Not x=0

[quick turret]

so u reflect in y axis

[pale tangle]

Yea

[sly elk]

I dont get it

soz for late reply I was revising chem like all day

[sly elk]

reflection of what

I thought that a y=0.5^x would go like

hold on

but at a slower rate or sum

@pale tangle @quick turret

[quick turret]

um

[sly elk]

like a lesser of a steeper

so a less steep gradient I mean

idk

[quick turret]

this is how i do it

it will never t ouch the x axis

[sly elk]

ohhhhhhhhhhhhh

I think I get it now

so it goes from 1

to

nearly 0

[quick turret]

doesnt matter how much it goes to i just did up to 4

so i can picture it

[sly elk]

in y axis

yh

[quick turret]

but it said x >= 0

so 0 is the minimum

[sly elk]

wdym

[quick turret]

question said

For x >=0

so x is bigger or equal to 0

[sly elk]

yh

[quick turret]

so 0 is the minimum value i can use

[sly elk]

but its not equal to zero is it

[quick turret]

but the inequality

[sly elk]

yh

[quick turret]

it has the thing underneath it

it means that 0 is included

[sly elk]

but is the inequality wrong

[sly elk]

yh

[quick turret]

no

i cant show the thing underneath it in text

thats why im doing >=

[sly elk]

ik but wouldnt the line never touch zero so wouldnt it be just <

[sly elk]

yh ik what u mean

but if u draw the line

it would never touch zero

right

[quick turret]

it will never touch the x axis

[sly elk]

yeah

[quick turret]

but x can be 0 because its 1/2^x

x is like the value

cant explain it

[sly elk]

so how come the question says <= and not <

[quick turret]

if it said > then

[sly elk]

yh I think I get it now

[quick turret]

1 is the minimum

because x>0

[sly elk]

so it would never toch the 1 acis

[quick turret]

noo like

any values of x

it will never touch the x axis

at 0

[sly elk]

I think I get it then

yeah

it wouldnt

[quick turret]

for 5 its gonna be

1/32

1/2 ^ 5

[sly elk]

But how come the graph starts at 1

like

[quick turret]

oh because

[sly elk]

the x acis 1

[quick turret]

1/2^0

is 1

[sly elk]

horizontal

[quick turret]

it doenst have to start at 1

[sly elk]

OHHH

wb if it was -1 or sumet

x^-1

[quick turret]

u cant though because

question said

for x>=0

[sly elk]

yh

that makes total sense

tysm

[quick turret]

np

[quick turret]

if x was -1 then

(1/2)^-1

thats 2

[sly elk]

so it would look like this?

[pale tangle]

Do uk what's reflections are ?

[quick turret]

that includes negative x values as well

[sly elk]

yh

[sly elk]

yeah but explain it in this context

please

[pale tangle]

So if I say

[sly elk]

😭😭 ive always hated thingy graphs like the f(x) but I know what u mean like putting the -x inside the brackets fliped the entire thing

flips with the y axis

[quick turret]

0.5 = 2^-1 right

[sly elk]

this makes more sense

[quick turret]

its what he showed

but more simplified

[sly elk]

yes

[quick turret]

so 0.5^x = 2^-1(x)

u got the x and u just multiply the powers

-1(x) = -x

[sly elk]

yh

[quick turret]

so u know that , that graph is a y-axis reflection of y = 2^x

[sly elk]

u draw the reflected

yh

[quick turret]

i would draw y = 2^x feint lines

then reflect it

[quick turret]

ye

[sly elk]

yh

tysm

[quick turret]

red line is y =2^x

reflected it to give y = 2^-x which is also y = 0.5^x

ig this is a faster way but if u forget this u always got the value method

[sly elk]

yhh

but I dont think the original Q would come up on a gcse

they would ask the standard ones woudlnt they

[quick turret]

know how to do it when it says like

y = pq^x

then it says to find out p and q

u gotta use coordinates

they will have pre drawn the graph for u

[sly elk]

wdym I meant like, wait let me get a Q that I remember this might take some time

so

https://mathsupgrade.co.uk/uploads/1/3/2/8/132853326/non-linear_graphs_mix_and_match_solutions_mathsupgrade_co_uk.pdf

it was this sort of Q

this

[quick turret]

wasnt this the

math paper

or not idk

but

its

D
F
A
H

[wide hemlock]

similar

but yh pretty much the same question lol

[pale tangle]

D is wrong

[sly elk]

this is from a past paper yh

[sly elk]

C F A H ?

thats such a fitting question bcz the other Qs that I remember seeing are piss easy like from this topic

[quick turret]

o D is cos x