Sec 3 Na Math
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Q1:An approximate method for converting temperature from deGrees Celsius (C) to Fahrenheit (F) is to double the Celsius temperature and add 30.
Using this method
a) write down the formula express F in terms of C
Q2:Look at the sequence 4,7,10,13,16,...
For this sequence,find
the nth term
Q3.The number 60,written as the product of its prime factors,is 22(the behind 2 is the small 2. which mean is on top of 2) x 3 x 5
a)Write 72 as the product of its prime factors
b)Use the results of part(a) to find
(i)the highest common facor of 60 and 72
(ii)the lowest common multiple of 20 and 72.
(iii)the lowest number k suck that 60k is a perfect square.
Q4.The lengths of the sides of a quadrilateral are x cm, (x+3) cm ,(x+4)cm and (2x-1)cm.
(a) Find and simplify an expression for the perimeter of the quadrilateral.
(b) Given that the perimeter is 26cm, find the length of the largest side.
Pls give mi the working and answer together. This is my Sec3 Mid-yr P1 2007 -
F = 2C + 30Originally posted by FaTal.ZenGetSu:Q1:An approximate method for converting temperature from deGrees Celsius (C) to Fahrenheit (F) is to double the Celsius temperature and add 30.
Using this method
a) write down the formula express F in terms of C
Aritmethic ProgressionOriginally posted by FaTal.ZenGetSu:Q2:Look at the sequence 4,7,10,13,16,...
For this sequence,find
the nth term
a = 4, d = 3
nth term = a + (n-1)d = 1 + 3n -
1a --> C=2f+30
i think. long time no touch maths.
2 --> 3N+1
i think so.
3--> i don't get no. 3 because product of 60 prime factors should be 30 = 2 x 3 x5?
4a--> perimeter = x+ x+3 +x+4 + 2x-1
---> perimeter = 5x+6
b- --> if perimeter = 26,
---> 26=5x+6
20=5x
4=x
so longest length --> x+4 = 8cm. -
your question very funny... maybe you typed wrongly...Originally posted by FaTal.ZenGetSu:Q3.The number 60,written as the product of its prime factors,is 22(the behind 2 is the small 2. which mean is on top of 2) x 3 x 5
a)Write 72 as the product of its prime factors
b)Use the results of part(a) to find
(i)the highest common factor of 60 and 72
(ii)the lowest common multiple of 20 and 72.
(iii)the lowest number k such that 60k is a perfect square.
anyway, 60 = 2^2 * 3 * 5
a) 72 = 2^3 * 3^2
b)
i) Highest common factor = 2 x 2 x 3 = 12
ii) 20 = 2^2 * 5
LCM = 2^3 * 3^2 * 5 = 360
iii) 60k = 2^2 * 3^2 * 5^2 (perfect square)
k = 3 * 5 = 15
a) Just add all up = perimeterOriginally posted by FaTal.ZenGetSu:Q4.The lengths of the sides of a quadrilateral are x cm, (x+3) cm ,(x+4)cm and (2x-1)cm.
(a) Find and simplify an expression for the perimeter of the quadrilateral.
(b) Given that the perimeter is 26cm, find the length of the largest side.
ans = 5x + 6
b) 5x + 6 = 26
x = 4
largest side is x + 4 cm = 8cm (find every side to determine largest) -
So for the answer for Q3 bii and biii is wad answer?
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didn't I give the answer already?Originally posted by FaTal.ZenGetSu:So for the answer for Q3 bii and biii is wad answer? -
Q5(A)According to the World Fact Book by CIA, it was recorded that the population of the world as at July 2006 was 6 525 170 264. Write down an appropriate estimate for 6 525 170 264 giving your answer in standard form.
(b)In 2005,a South Korean scientist from Yonsei University Centre of Atomic Wires and Layers has developed the world"s thinnest metallic wire for semiconductor chip. The wire measures just two nanometres in width. Express 2 nanometers in standard form.
Q6: Factorise the following algebraic expressions completely
(a) 4x^2 +16
(b) 15k^3 - 49k^2 + 35k -
i dun know which one to write the answer
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a.)6.53*10^9Originally posted by FaTal.ZenGetSu:Q5(A)According to the World Fact Book by CIA, it was recorded that the population of the world as at July 2006 was 6 525 170 264. Write down an appropriate estimate for 6 525 170 264 giving your answer in standard form.
(b)In 2005,a South Korean scientist from Yonsei University Centre of Atomic Wires and Layers has developed the world"s thinnest metallic wire for semiconductor chip. The wire measures just two nanometres in width. Express 2 nanometers in standard form.
Q6: Factorise the following algebraic expressions completely
(a) 4x^2 +16
(b) 15k^3 - 49k^2 + 35k
b.)2*10^-9
6a.) 4(x^2 -4) +32 ????not sure
6b.) k(15k^2-49k+35) then factorise the inside. but the inside cannot be factorised into nice numbers. use th -b plus minus (root b^2 -4ac)/2a formula. -
sec 3NA dun learn aritmethic progression if i am not wrong~Originally posted by eagle:Aritmethic Progression
a = 4, d = 3
nth term = a + (n-1)d = 1 + 3n -
i think for 6a question supposed to be 4X^2-16.
where upon factorizing will be..
--> difference of 2 squares.
(2x+4) (2x-4).
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oops i forgot ....sianz...too long nvr factorise liaoOriginally posted by stellazio:i think for 6a question supposed to be 4X^2-16.
where upon factorizing will be..
--> difference of 2 squares.
(2x+4) (2x-4). -
ya apgp is a level =.=Originally posted by hiphop2009:sec 3NA dun learn aritmethic progression if i am not wrong~ -
my time was O levelsOriginally posted by unclebutcher:ya apgp is a level =.=
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but that question no need provide workings one leh.Originally posted by hiphop2009:sec 3NA dun learn aritmethic progression if i am not wrong~
just put answer can le. -
ya, i noe. later de O level apgp was pushed to A level.Originally posted by eagle:my time was O levels -
Then can anyone teach?Originally posted by hiphop2009:ya, i noe. later de O level apgp was pushed to A level.
Cus i hate to guess and check... waste of time sia...
^^ -
eh....i forgot liao.....Originally posted by popikachu:Then can anyone teach?
Cus i hate to guess and check... waste of time sia...
^^
hmm, eagle u noe? -
about? APGP?Originally posted by hiphop2009:eh....i forgot liao.....
hmm, eagle u noe?
Ask unclebutcher for his notes lor.... -
If it's really 4x^2 + 16 leh?Originally posted by stellazio:i think for 6a question supposed to be 4X^2-16.
where upon factorizing will be..
--> difference of 2 squares.
(2x+4) (2x-4). -
den i duno how to factorize, too long never do maths.Originally posted by ndmmxiaomayi:If it's really 4x^2 + 16 leh?
but wah lan, sec 3na lvl got learn until so high meh.
should be difference of 2 squares leh. -
Can just leave it as 4(x^2 + 4) ma... still correct, at secondary level.Originally posted by stellazio:den i duno how to factorize, too long never do maths.
but wah lan, sec 3na lvl got learn until so high meh.
should be difference of 2 squares leh. -
Nah. Can'tOriginally posted by ndmmxiaomayi:Can just leave it as 4(x^2 + 4) ma... still correct, at secondary level.
Q6a.
4x^2 + 16
= 4(x^2 + 4)
=4(x^2 + 2^2)
= 4(x + 2)(x + 2)
=4(x + 2)^2
Remember
(a^2 - b^2) = (a + b)(a - b) -
Originally posted by Darkness_hacker99:
huh u dun make sense leh.
=4(x^2 [b]+ 2^2)
= 4(x + 2)(x + 2)
=4(x + 2)^2
[/b]
how come 4(x^2 + 2^2) = 4(x + 2)(x + 2)
only 4(x^2 + 4x + 2^2 = 4(x + 2)(x + 2) -
By the way,there's no method for nth term.U need to use logic.i also dunno how to do coz no method