Maths help please. (1 Viewer)

[mastistar]

http://www.boardofstudies.nsw.edu.au/schoolcertificate/2007/mathematics-sc-test-07.pdf

This is for the non calculator section. Thanks for your efforts.

The questions i need help with are:

Q ) 8

Q ) 9

Q ) 11

Q ) 15

Q ) 17

Q ) 18

Q) 19

Q ) 24

Thank-you very much.

 

[tommykins]

8) break it up into a triangle, rectangle and then another triangl.e indiivudally calculate the area of each and add up

9) sub in x = -2 to find value of y, then you have your point K

11) DE/AB = EF/BC , thus they are similar triangles and corresponding angles

15) tan is opposite/adjacent, so
tan@ = 2/3

2/3 = 6/x
2x/3 = 6
2x =18
x = 9

17) triangle inside the circle is isosceles since the lengths of two sides are the radius of the circle. since 50* is base angle, then the other base angle is also 50. 90-50 =40* = m

18) use ur indices law, 3*10^4*2*10^-6 = (3*2)*(10^4*10^-6) = 6*10^-2

19) equate y = x^2+3, we have y = 7 so 7 = x^2+3 , x^2 = 4, x = +-2, but we have x = -2 already so x must be 2

24) <MKN = 30 (bisected) by the line KN.

< sum of triangle = 180
we know triangle KMN is isos since KM = KN, so the base angles are equal

thus - 2<KMN = 180-30 = 150
<KMN = 75

 

[freedragon]

8) y= -4x
x=-2 therefore y=8

9) n < -2 x 3
n< -6

11) simular triangle proof rule: SAS (side angle side) the matching sides are in the same ratio 2:1, and the right angle in between these 2 sides is common. therefore the triangles are simular

15) A= half bh
the perpendicular height of the triangle is 4. The base is 6. therefore, u should draw a rectangle that has an are of 12cm squared.

17) the triangle is iscosolese because of the 2 radii. therefore the angle in between m and 90 deg. is 50 deg. m=180-90-50=40 deg.

18) 6 x10^-2 (30000 x 0.000002 = 0.06)

19) 2. it is a parabola, so the curve is symmetrical. put it back into the equation and u will c

24) angle k is 60 deg. because it is an equilateral triangle. the angle k is cut in half by the smaller isoscolese triangle so that angle mkn is 30. the two angles at the base of triangle mkn are equal, so angle kmn + angle knm = 180-30=150. angle kmn and knm are equal so angle kmn = 150/2=75

hope i helped, im confusing sometimes

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[mastistar]

thx..guys

 

[silence--]

3*10^4*2*10^-6


multiplication can be done in any order

so multiply the 2 and 3, you get 6

then 10^4 and 10^-6, use your index laws and add the two powers since you're multiplying. 4 + (-6) = -2

so you have 6*10^-2 or 0.06

 

[freedragon]

think of it this way. you multiply the base numbers (2 and 3) to get 6 right?

the x10 bit says the same but what happens when you do 2^4 x 2^-3 for example?

you get 2 to the power of 1 because 4+ (-3) =1. when you multiply powers, they add together. try it!

so back to the question. if you multiply x10^4 and x10^-6, you add the 2 powers, which are 4 and -6 to get x10^-2.

so in the end, when you multiply the base to get 6, and the x10 powers to get a power of -2, you get the answer 6 x10 to the power of -2. (6x10^-2)

do you get it?