@humble dirge
#A Level Maths- work out the area from a graph
humble dirge
Just integrate?
haughty iris
like where has the k come from
humble dirge
Wait can I get a better screenshot/picture of the answer
humble dirge
oh Im a bit dumb
right so basically you know the equation's form because you know that the roots are -1 and 2
haughty iris
yeah
humble dirge
This means that y = k(x+1)(x-2) where k is some constant because all we know is the roots
k can be anything and the roots will be at -1 and 2 still, so we have to figure out what that is
haughty iris
But why is there a k involved. Isn’t that only for like direct and indirect proportion?
humble dirge
k is just a random letter, could be a, b, c, or any other letter
haughty iris
But what does ‘k’ resemble
humble dirge
normally people use k or c for constants unless theres multiple
humble dirge
But what does ‘k’ resemble
Really just any number you'd multiply the equation by, I can show you on desmos if you need
haughty iris
Because the thing is I would of been able to work it all out and my answer would of been 4.5, not 9 because I wouldn’t of times it by 2
The answer was 9 btw
haughty iris
Thanks
humble dirge
As you can see, it does matter what the k is because it would change the area under the graph
If you assume that it isn't needed (i.e. k = 0) then you don't get the line that is on thee graph given
haughty iris
Ok
So if it was 5 marks I doubt a k would be needed
Because 8 marks for this question seems like quite a lot
humble dirge
As you can see, it does matter what the k is because it would change the area un...
I also just realised those were wrong but you get the idea
humble dirge
So if it was 5 marks I doubt a k would be needed
Id say something like that, because integrating isn't the hardest part of y12 maths
haughty iris
Yeah
humble dirge
well id argue its up there but it doesnt give you many marks
haughty iris
Ok, well thanks a lot mate I really appreciate it