C2 DOUBT edexcel

[halosh92]

A=1, (5+or-sqrt 105)/8

please show workings i need to know how to get da ans

Thanks

which paper is this?

[Amr Fouad]

can sme one solve this ques

the coefficient of x³ in the epansion of (2+x)(3-ax)⁴ is 30
find the values of the constant a.

please show step by step working
Thanks

here u go..

@halosh, i answered ur angle question, check the post

[halosh92]

here u go..

@halosh, i answered ur angle question, check the post

 thx AF  but i did the whole thing its correct except when i got stuck at solving the cubic function..how do i do that?

[past-papers]

For C2, you will always get easy cubics and thus you will always be able to find one factor!!

In this case, you can see that if a=1 the equation is equal so you realise that (a-1) is a factor.

now divide by (a-1) and you will get a quadratic which you can easily factorise again...

[halosh92]

For C2, you will always get easy cubics and thus you will always be able to find one factor!!

In this case, you can see that if a=1 the equation is equal so you realise that (a-1) is a factor.

now divide by (a-1) and you will get a quadratic which you can easily factorise again...

thx aloot
but isnt this a C2 question?

[past-papers]

You tell me You asked it haha

It looks like a C2 but it's been more than 2 years since I did C2 so I can't be sure!!

[halosh92]

You tell me You asked it haha

It looks like a C2 but it's been more than 2 years since I did C2 so I can't be sure!!

haha lool no i didnt ask the question someone else did
XD thx alot anyways

[Amr Fouad]

lool yes past papers is right..

firt you have to find the factors of the constant, in this case 30:

1,30,15,2,5,6,and the negatives of each..

and we know that (a+y) is a factor when f(-y) =0..therefore, a=1 obviously gives us zero,

and so (a-1) is a factor...

do long division, get the quadratic function, and find the solutions..

sorry 4 the late reply, i had to go lol