Math Is Fun Forum

  Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ • π ƒ -¹ ² ³ °

You are not logged in.

#2 Help Me ! » Cylinder, finding r and stuff » 2008-03-09 12:17:48

mathsux
Replies: 5

From the image attached, the outside square has side lengths of 30cm.

The radius of each of the circles is " r " cm.

Use the length of the rectangle (i.e circumference of the circular base) to find the possible values of " r ".

Height of cylinder = 30 - 4r
Length of cylindr = 2nr where n = pi.
T.Area of Square = 900 cm^2

#3 Re: Help Me ! » A Water Slide question » 2008-03-09 09:18:01

Identity, I get "Error: Argument error" when I try to solve using the function of x method you wrote up there.

#4 Help Me ! » A Water Slide question » 2008-03-08 21:54:15

mathsux
Replies: 5
This slide is modeled by the equation of y =((x - e)(x - f)(x - g))/3000

When the graph is drawn, there are the following points on the graph line:

(0, 7.6)
(19,0)
(20, -1/3)

Using the points, find e, f and g.

Doing some pretty complex math, I have found that e, f, g can be found through paper solutions.

But this is a mere part-question in 3 different questions used in an exam. I have only a limited amount of time, so I use the TI-89 Titanium graphics calculator.

Is there any way on this calculator that I can simultaneously solve for e, f and g.

I have tried: solve(-e*f*g=7.6 and ((19-e)*(19-f*)(19-g))/3000=0 and ((20-e)*(20-f)*(20-g))/3000=-1/3, {e,f,g})

But it displays "Too Few Arguments" !!! WHY!!!!?????/

Help please.

#5 Help Me ! » Probability using Counting Techniques » 2007-10-10 21:33:59

mathsux
Replies: 5

When 4 guys and 4 girls are arranged in a row, find the probability that:

2 guys have three seats between them?

-ms

#6 Help Me ! » Bearings: Bearings Make Me Cry » 2007-08-20 19:26:44

mathsux
Replies: 2

[i] An observer on top of a tower spots a fishing boat on a bearing of 340T at an angle of depression of 1.2 degrees at 1000 hours. At 1045 hours, the same boat is on a bearing of 070T at an angle of depression of 2.3 degrees. The observer is 60m above sea level.

I need to calculate the bearing, correct to one decimal place, from the trawler's 1000 hour's position and it's 1045 position.

Mathsux!

#7 Help Me ! » Further Trig: Bearings Question » 2007-08-20 01:20:07

mathsux
Replies: 1

i'm having trouble both understanding the question and drawing up a diagram.

Key: 026T = 26 Degrees True North

From point A, a lighthouse is on a bearing of 026T and the top of the lighthouse is at an angle of elevation of 12 degrees. From a point B, the lighthouse is on a bearing of 296T and the top of the lighthouse is at angle of elevation of 14 degrees. If A and B are 500 metres apart, find the height of the lighthouse, to the nearest metre. (Metric Metre)

Pleeeeeeaaase help!

mathsux

#8 Re: Help Me ! » Graph of y = x^2 + 6x + 2 » 2007-08-12 21:22:22

I think I've done something wrong...I must've. If I check using the calculator the graph of -x^2+6x+2=y is like the opposite of the graph of -(x-3)^2+11=y (inverse)

#9 Help Me ! » Graph of y = x^2 + 6x + 2 » 2007-08-12 20:35:29

mathsux
Replies: 4

Okay,

I need a non-calculator method for this problem.

I can work out the Turning point and put it into TP form, but I have massive difficulty finding the X-intercepts.

TP Form: y = -(x-3)^2 + 11 ---> Turning Point = (3, 11)

Y Intercept ---> y = 2

I just need the X-Intercepts!

PLz help.

Thanx.

#11 Help Me ! » 1. Average Speed of the Car » 2007-08-07 20:06:22

mathsux
Replies: 5

The distance of two towns is 120km by road and 150km by rail. A train takes 10 minutes longer than a car whose average speed is 10km/h less than the train's average speed. The purpose of this problem is to find the average speed of the car.

a) Let the average speed of the car be x km/h and the time taken by the car be t hours. Show the information gives:

xt = 120 (1)
(x+10)(t + 1/6) = 150 (2)

b) Subtract (1) from (2) to obtain a linear equation linking x and t.

I have no idea how to do this.

Please Help. It will be on a test tomorrow.

-mathsux

#12 Introductions » Greetings... » 2007-08-06 22:25:10

mathsux
Replies: 2

Hi, my name is mathsux.

Okay, maths doesn't really drag, but that's how I view my performance in Mathematics. I'm actually 15 and am in Year 10 (Australia/VIC Standard).

I specialize in English and Language, but drop quite a bit in more logical subjects.

A little about myself:

Real NickName: Bennish
Age: 15
Interests: Technology, Gaming, Literature, Linguistics
Hobbies: Guild Wars - R/Mo, Oblivion, Photoshop-ing, DreamWeaving, drawing, eating, doing English homework.

Thanks.

Mathsux

Board footer

Powered by FluxBB