IGCSE MATHS Doubts

[PeaceMaker]

ALWAYS remember ..

for addition and multiplication ..

LB = LB + LB

LB = LB x LB

UB = UB + UB

UB = UB x UB

for subtraction or division .. (is different)
LB = LB - UB

LB = LB/UB

UB = UB - LB

UB = UB/LB 

consider solving some sums u'll get them  .. these kinda ques usually appear in paper 2 .. (jus solved a couple of them few mins ago)

I dont really get it. If you would solve me some questions from the past papers with the formula's you provided, it would be really helpful.

[Vin]

Ohhh!! sorry couldn;t interpret the typin ..

[Vin]

I dont really get it. If you would solve me some questions from the past papers with the formula's you provided, it would be really helpful.

why dont u post some papers ..

[Fastal]

i know its perpendicular to the invariant line, but how far away from the base is it?

lets say "_" got stretched, and the image also moved away, in this case where is the invariant line?-------

->               _    __

[Ghost Of Highbury]

The base didn't change its shape. Thus, the x-axis is invariant.

[Fastal]

The base didn't change its shape. Thus, the x-axis is invariant.

but it can be y=1 axis too right?

[Ghost Of Highbury]

Anything parallel to x-axis.

[Fastal]

but how do you know which one it is, cuz to find the scale factor you need to know the exact invariant line.

[Baladya]

srry to interrupt, but do u guys know how can we use stuff like square root on the forum? I've seen a post in this topic that used that (the font looked weird tho)

[ksitna]

is it,
(x-3)/4 = 4/(x-3)
then,
=> (x-3)(x-3) = 4*4
=> x² -6x +9 = 16
=> x² -6x -7 = 0
=> (x+1)(x-7) = 0
=> x = -1 , x = 7

yeah thts what i meant
thanks

but it said simplify as a fraction

i still dont know how to do it

[PeaceMaker]

May/june 2003 Paper 2 Q.2, 7 & 6, Im confused, if anyone knows how, please do tell i'd be grateful

[@d!_†oX!©]

yeah thts what i meant
thanks

but it said simplify as a fraction

i still dont know how to do it

umm..ok, try this
(x-3)/4 = 4/(x-3)
=> (x-3)/4  -  4/(x-3)
=> x² -6x -7 / 4x -12

[Ghost Of Highbury]

q2) use the graph for a. for b) 5/7.85 *90 = 57.32
q7) 3<2x-5<7

     3+5<2x<7+5

     8/2<x<12/2

      4<x<6

q6) 17.5*11.5 = 201.25

[ksitna]

umm..ok, try this
(x-3)/4 = 4/(x-3)
=> (x-3)/4  -  4/(x-3)
=> x² -6x -7 / 4x -12

uh im sorry
i dont really get it
how did u get -7?

[PeaceMaker]

Dammit from all that math solving i made a mistake! i meant 2005 <____< but seriously, thank you for the response +rep