Hi can we use the caregiver’s address for one phase and use our own address (in nric and currently staying) for another phase?

Hi anyone with review or promo referral code for farrer park or toa payoh pls?

hi i suppose the question is to differentiate this wrt x:

y = 10 / (1 + x^2)
y = 10* (1 + x^2)^-1

dy/dx = 10 * (2x) * (1 + x^2) ^ -2
= 20x / (1 + x^2) ^2

the main function is (1 + x^2)^-1
differentiate the function (1+ x^2) –> 2x
and reduce the whole function’s power by 1, i.e. the power becomes -1 -1 = -2

general rule:
differentiate constants –> 0
differentiate x –> 1
differentiate x^n –> n* x^(n-1)

reddiechan:

virgo:

Need help on these 2 questions.... many thanks !!!


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(a) 6x2 + 12 x - 90
= 6 (x2+2x-15)
= 6(x-3)(x+5)

(b) 6(x-7)^2 + 12(x-7) - 90
= 6(x2-14x+49) + 12x - 84 - 90
= 6x2 - 6(14x-49) + 12x - 84 - 90
= (6x2 + 12x - 90) - 6(14x-49)
= 6(x-3)(x+5) - 6(14x-49)
= 6[(x-3)(x+5) - 7(2x-7)]

for part b, again notice the similarity with part a, so just sub x = x-7 into part a answer:
6(x-7)^2 + 12(x-7) - 90
= 6 ((x-7) - 3) ((x-7) +5)
= 6 (x - 10) (x -2)

M-Help:

Dear studybuddy


There seems to be a careless error in your final answer to part (ii). Pls check and confirm.

oh yes, careless! thanks for pointing out

virgo:

Need help on these two questions... many thanks !!


http://i43.tinypic.com/35b89wy.gif\">

a.
first term is 3x^2 so it has to be the form of (3x +...y) *(x + ...y )
the coefficient of y will have to give a multiple of 54
one of --> 1, 54 or 2, 27 or 3, 18 or 6, 9
coeff of xy = 9, so the answer has to be
(3x - 9y)*(x + 6y)

b.
consider the similarity to part a.
use substitution of x= (3x - 8y), you will get:

(3 (3x - 8y) - 9y) * ((3x - 8y) + 6y)
= (9x -24y - 9y) *(3x - 8y + 6y)
= (3x - 33y)* (3x - 2y)

do ask if u need more clarifications! :imcool:

aceurmaths:

clblinym:

Need help with a question... many thanks. Amy

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You still need any help ?

Q12 part a.
height of water = 3/8 * 48cm = 18cm
surface area = base area + rectangular area + 2 trapezium areas + slant area
= 90 *56 + 56 *18 + 2* (.5*(90+75)*18) + 56* 23.4
= 10330 = 10300 sqcm (to 3sf)

the slant height is 23.4cm using pythagoras theorem for bottom right triangle with other lengths 18cm and (90-75) = 15cm.

part b.
volume of water in part a = 75 * 56 * 18 + 0.5 *15*56*18
= 83160 cm3
25% increase = vol of 9 cylinders = 83160*0.25 = 20790 cm3
vol of 1 cylinder = 2310 cm3
= pi*r^2 * h
r^2 = 2310 / (3.142 * 16) = 45.950
r = 6.7786
diameter = 2r = 13.557 = 13.6cm (to 3 sf)