Qualification > Math
IGCSE MATHS Doubts
Vin:
--- Quote from: saleemsamer on May 07, 2010, 09:51:15 am ---hi guys can some1 post the diagram for oct/nov 09 p4 question 4a
and can sum1 plz explain questions 2a)iv and b)ii (same paper)
thx in advance :)
--- End quote ---
n also b) ii)
theres a great method my teacher taught me...
(y) x U = X
(a b) (-1 -4 -4 ) ( -1 -4 -4)
(c d) (1 1 3 ) = ( 2 5 7 )
multiply a b c d in matrix y to matrix U (they are the positions of the image, row 1 is x axis row 2 is y )
( (-a + b) (-4a+b) (-4a + 7b) )
( (-c+d ) (-4c +d) (-4c+ 7d) )
now solve any two equation my simultaneous method...
so, -a +b = -1 (because the position of this equation is corresponding to matrix "X", look for the colours)
-4a + b = -4
by solving u get a = 1 , b = 0
same for 'c' and 'd' ..u get d= 1 and c = -1
i dont expect u to understand but this method is really good n its really difficult for me to teach online..:(
read it n try to follow the steps while solving the paper u might get it...:) :)
Dark Prince:
--- Quote from: ~VIN1094~ on May 07, 2010, 12:05:54 pm ---a iv) shear, factor = 1 , y-axis invariant line
u should know the formula
shear = distance moved due to shear
----------------------------
perpendicular dist. frm invariant
--- End quote ---
Actually i did this Q da sme waybut in da mark scheme da answer is Scale factor= -1......how is da scle factor -ve
Snake:
- scale factor can either mean inverted picture or smaller then original picture
Vin:
--- Quote from: hotmail16 on May 07, 2010, 01:03:36 pm ---Actually i did this Q da sme waybut in da mark scheme da answer is Scale factor= -1......how is da scle factor -ve
--- End quote ---
oh my bad... the image moves to the left is -ve and to the right is positive.. :)
sorry about that mistake..i'll amend it
Dark Prince:
can u explain it .....y is da scale factoe -ve wen we move da image to left.....nd is this rule same 4 all quadrants? wat abt 3rd quadrant......wat if da image is on x-axis.....nd wat abt stretch( wen is its scale factor -ve).....thnkx.
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