Questions

[costargh]

500= a + ( n -1) * d

500= 250 + (n - 1) * 26
 
500 = 250 + 26n - 26

500 = 224+ 26n

276= 26n

276/ 26 = n

n = 10.6154
The first term (n) to pass 500 is therefore 11

[Rosie]

Q. A square has an area of 169cm². What is the length of the diagonal?

similar triangles:
Q. A hill has a gradient of 1 in 20, i.e. for every 20m horizontally there is a 1 m increase in height. If you go 300m horizontally, how high up will you be?

thanx

[clinton_09]

for the similar triangle question i think you would just divide 300 by 20 which will give you 15m

[lwine]

1. The area of a square is the length of its side squared. Therefore, This is the length of its side.

To find the diagonal, we can use pythagoras theorem:

2. If there is a 1m rise for every 20 meters, and we travel for 300 meters, then the number of meters we rise is equivalent to the number of times we travel 20 meters. Therefore, 300/20 = 15 times, so we rise a total of 15 times 1 meter, which equals 15 meters.

[jsimmo]

Q. A square has an area of 169cm². What is the length of the diagonal?

similar triangles:
Q. A hill has a gradient of 1 in 20, i.e. for every 20m horizontally there is a 1 m increase in height. If you go 300m horizontally, how high up will you be?

thanx

It's easier just to square root 169

√169 = 13cm

[bucket]

er thats what he did lol.

[jsimmo]

he didnt explain it well if it was

[Rosie]

Q. A man whose eye is 1.7m from the ground when standing 3.5m in front of a wall 3m high can just see the top of a tower that is 100m away from the wall. Find the height of the tower.
How would I make the draw the two similar triangles because I can't understand what the question is saying?


Q. A spotlight is at a height of 0.6m above ground level. A vertical post 1.1m high stands 3m away, and 5m further away there is a vertical wall. How high up the wall does the shadow reach?

thanks

[cara.mel]

First one:
If you draw it out, it looks like this. Always draw the question out. (tower is blue, wall is red, person is a lovely Stick Figure


Answer below (try to work it out for yourself first )
1.3/3.5 = x/(100 + 3.5)
x = 103.5*1.3/3.5 = 38.4
This is the tower's height above eye level. The actual height of the tower = 38.4 + 1.7 = 40.1m

Second question is essentially the same with different numbers

[ninwa]

hey, has any1 in this forum been to tsfx further intense workshops last semester???
how was?
i reallly need feedback? is it worth going? do they give you bound reference? good notes?

[Rosie]

Q. A and B are two positions on level ground. From an advertising balloon at a vertical height of 750m, A is observed in an easterly direction and B at a bearing 160 degrees. The angles of depression of A and B as viewed from the balloon are 40 degrees and 20 degrees respectively. Find the distance between A and B. 

Can someone help me with this question. I'm finding it hard to draw a diagram.

[Rosie]

*bump

[/0]

Q. A and B are two positions on level ground. From an advertising balloon at a vertical height of 750m, A is observed in an easterly direction and B at a bearing 160 degrees. The angles of depression of A and B as viewed from the balloon are 40 degrees and 20 degrees respectively. Find the distance between A and B. 

Can someone help me with this question. I'm finding it hard to draw a diagram.

Let the balloon be at point O. Let the horizontal distance of points A and B from the balloon be and respectively.
From the information:





Now, by the Law of cosines,





This comes out to . You could probably use componentizing to solve the last bit instead of the cosine law... and there's probably an easier way to do this...

[Rosie]

Urgent question!!!

MATRICES
Q. How many of the following five sets of simultaneous linear equations have a unique solution?

1. 4x + 2y = 10
    2x + y = 5

2. x = 0
    x + y = 6

3. x - y = 3
   x + y = 3

4. 2x + y = 5
    2x + y = 10

5. x = 8
    y = 2

Answer choices
A. 1
B. 2
C. 3
D. 4
E. 5

How do i work out the answer especially the ones that dont have an equation, like x = 0, x = 8 etc.

[Mao]

2 and 5 are trick sets

for 2, if x=0, then y must be 6. distinct solution

for 5, x=8, y=2, distinct solution