[megank]

(Original post by Konshi)
Edit: Nvm just figured it out, should've really got that in the actual exam lol

y=10-3x
so sub this into (xy) so it will be 10x-3x^2 = 3
put into brackets and there you go

*sorry i posted it before realizing youve editted it... anywya i cant delete this post

[Genesis2703]

(Original post by megank)
Hey guys.. for geometric progression, can the ratio be a negative value?

Yes it can

[megank]

(Original post by Genesis2703)
Yes it can

Can you help me with one question??
why is the answer to 9(ii) is only the plus value??

[peachesandcream77]

(Original post by megank)
Can you help me with one question??
why is the answer to 9(ii) is only the plus value??

Because the negative value is -1.6
and r has to be between -1 and 1

[megank]

(Original post by peachesandcream77)
Because the negative value is -1.6
and r has to be between -1 and 1

Oh... Is that always the case for geometric series? or just to this question??

[erniiee]

(Original post by Genesis2703)
i got 89 in c1... which I was unhappy with, BUT i only need 90+ on A2 units for an A* so I dont mind , I got 97 on Fp1 in january as well. I revised FP1 loads and neglected C1 which cost me :/

And yeah Lunch, but I say dinner :P

Ah I got 87, so annoying as I always thought C1 would be super easy. Ah well played with FP1! And true, I suppose all I need is an A in these units! Would've been nice to get some flawless UMS scores in the bag though.

(Original post by Konshi)
Yeah been playing around with it a bit more and it seems to do the trick

I also see that you're a fellow 2013 hopeful! (Although I'll be a reapplicant )

Ah okay

Aha yeah Oh, where did you apply this year?

[Genesis2703]

(Original post by megank)
Oh... Is that always the case for geometric series? or just to this question??

The sum to infinity for a geometric must always involve a ratio from -1 to 1.

(Original post by erniiee)
Ah I got 87, so annoying as I always thought C1 would be super easy. Ah well played with FP1! And true, I suppose all I need is an A in these units! Would've been nice to get some flawless UMS scores in the bag though.

Thanks, and yeah people and teachers at my school underrated C1 in terms of difficulty, they were too laid back.

[Konshi]

(Original post by erniiee)
Ah I got 87, so annoying as I always thought C1 would be super easy. Ah well played with FP1! And true, I suppose all I need is an A in these units! Would've been nice to get some flawless UMS scores in the bag though.



Ah okay

Aha yeah Oh, where did you apply this year?

I got 86 on my C1 retake, need 84 in this S1 to get an A overall if C2 doesn't go up. S1 is the bane of my life lmao.

Applied to Liverpool, Leicester, Cardiff and HYMS. Really need to ensure I ace the finals in a months time. Need 141 for an A* in Bio, 72/80 for an A* in Eng Lit, and I don't even know what I need for an A in chem, I'm resitting them all to try and boost up my mark!

Edit: nvm got it again lol

[megank]

(Original post by Genesis2703)
The sum to infinity for a geometric must always involve a ratio from -1 to 1.



Thanks, and yeah people and teachers at my school underrated C1 in terms of difficulty, they were too laid back.

but that wasnt linked to the sum to infinity it was just finding r from the equation r^3 -2r + 1 =0

[master y]

(Original post by Genesis2703)
The sum to infinity for a geometric must always involve a ratio from -1 to 1.



Thanks, and yeah people and teachers at my school underrated C1 in terms of difficulty, they were too laid back.

Hey, was this the C1 in Jan? Yeah i did this, was particularly a hard paper but got 94 ums, which im happy with!! I think C2 will be better tomorrrow though

[erniiee]

(Original post by Genesis2703)
Thanks, and yeah people and teachers at my school underrated C1 in terms of difficulty, they were too laid back.

Definitely my teacher is so bad, ha she's not being allowed to teach A Level next year!

(Original post by Konshi)
I got 86 on my C1 retake, need 84 in this S1 to get an A overall if C2 doesn't go up. S1 is the bane of my life lmao.

Applied to Liverpool, Leicester, Cardiff and HYMS. Really need to ensure I ace the finals in a months time. Need 141 for an A* in Bio, 72/80 for an A* in Eng Lit, and I don't even know what I need for an A in chem, I'm resitting them all to try and boost up my mark!

Ah okay Yea I hate S1, perms and combs are the bane of mine

Oh wow, good luck man!

[Genesis2703]

(Original post by megank)
but that wasnt linked to the sum to infinity it was just finding r from the equation r^3 -2r + 1 =0

It says the progression converges therefore the value of r have to be from -1 to 1 (as there is a sum to infinity)

(Original post by erniiee)
Definitely my teacher is so bad, ha she's not being allowed to teach A Level next year!

Seriously????? Unlucky :P

[megank]

(Original post by Genesis2703)
It says the progression converges therefore the value of r have to be from -1 to 1 (as there is a sum to infinity)



Seriously????? Unlucky :P

oh sorry! misread that, my bad

[Konshi]

Turns out I don't get it, 9b on Jan 2012 for solving the equations, help please!

[katles]

I am majorly stressing out about this, I'm trying to practice C2 all day today but my motivation levels are so low

[katles]

(Original post by Konshi)
Turns out I don't get it, 9b on Jan 2012 for solving the equations, help please!

You let y=sin(0.5x) and then use the quadratic formula to work out the x values, then substitute that back into the y=sin(0.5x) to get the real x values... If that makes sense ?

[Konshi]

(Original post by katles)
You let y=sin(0.5x) and then use the quadratic formula to work out the x values, then substitute that back into the y=sin(0.5x) to get the real x values... If that makes sense ?

Yeah I've worked it out now, thanks! Trig graphs always screw me over

[Genesis2703]

Is 0.5abSinC (for a triangle area) a radian formula, or does it work in degrees also, because I made a mistake earlier because I used degrees, althoug I didnt think it was a radians formula

[peachesandcream77]

(Original post by Genesis2703)
Is 0.5abSinC (for a triangle area) a radian formula, or does it work in degrees also, because I made a mistake earlier because I used degrees, althoug I didnt think it was a radians formula

It also works in degrees
but make sure if you're using a radian as theta, then put your calculator in radian mode.

[Genesis2703]

(Original post by peachesandcream77)
It also works in degrees
but make sure if you're using a radian as theta, then put your calculator in radian mode.

Oh it was for one question, you were given the angle in radians, but for some reason i did it in degrees, but got the wrong answer, even though I was in degrees mode :/