Mathematics - 11 June 2007

A helicopter rises at the rate of 8 feet per second from a point on the ground 60 feet from an observer.

Find the rate of change of the angle of elevation when the helicopter is 25 feet above the ground.

Explain your work, and good luck! :)

2007-06-11 09:39:09 · 4 answers · asked by Anonymous

2007-06-11 09:33:16 · 4 answers · asked by Anonymous

Need help simplifying
(2d^4+2d^3-9d^2-3d+9) / 2d^2-3

2007-06-11 09:33:00 · 2 answers · asked by D M 1

What is a and b, i need working to be shown.
This table shows the weights of 100 children in year 7,
An estimate of the mean weight of the children is calculated as 44 kg.

Weight,w(kg) - Frequency
20 < w 30< w 40 50 60

2007-06-11 09:32:53 · 3 answers · asked by Anonymous

How would you simplify this?

After dividing 80,000 / 587, would I divide 0.0067 with all the terms in the brackets.

80,000 = 587 [ 1 - (1.0067)^(-12 t) / 0.0067 ]

To make it clear, the first part in the brackets [ ] divided by 0.0067

I suppose I have to use logarithms... ?



Thx! :D

2007-06-11 09:29:25 · 3 answers · asked by jill b 1

1. If y varies inversely as x and y = 25 when x = 2, find y when x = 5.

2. Find sin 54° to the nearest thousandth.

3. Use I = Prt to find r if I = $370, P = $2000, and t = 3 years.

2007-06-11 09:21:16 · 12 answers · asked by Kel 1

2007-06-11 09:18:11 · 8 answers · asked by Heather 1

Consider a multiple regression of Y (gas mileage) on two predictor variables X(1) (vehicle weight) and X(2) (engine type). Suppose X(2)is an indicator variable that takes the value +1, if the engine is fueled by gasoline and 0,if the engine is fueled diesel. Is there some numeric value for variable X(1) such that if X(1) is less than this value the mean fuel economy for gasoline vehicles will be lower than the mean fuel economy of the diesel vehicles, but if X(1) is greater than this value,the mean fuel economy for gasoline vehicles will be higher than the mean fuel economy of the diesel vehicles.

Yes, there is such a value.
No, no such value exists.
The question depends on the sign of the slope parameter for variable X(1)
You can only answer this question for a specific regression on a specific data set.

2007-06-11 09:15:53 · 2 answers · asked by Anonymous

Is it possible to define f(1) in such a way that f is continous throughout the x axis? please show work

2007-06-11 09:12:03 · 4 answers · asked by sammiballer99 1

these are the possible solutions to choose from in the back of the book......


a. 12.4

b. 13.0

c. 15

d. 15.3

or none of these

2007-06-11 09:09:27 · 4 answers · asked by chris 2

possible solutions....



a. (-1)<-2, 2, 1>

b. (-1/3)<-2, 2, 1>

c. (-2/9)<-2, 2, 1>

d. (-1/9)<-2, 2, 1>

e. <0, 0, 0>

f. (2/9)<-2, 2, 1)

g. (1/3)<-2, 2, 1>

h. <-2, 2, 1>

or is it none of these?

2007-06-11 09:05:43 · 1 answers · asked by chris 2

2007-06-11 09:02:01 · 2 answers · asked by MaeMae 1

I know the answer to this problem because it's from an old New York State Math B Regents, but I don't know how to get it.

The Question:
On a monitor, the graphs of two impulses are recorded on the same screen, where 0 degrees (is less than or equal to) x degrees < 360 degrees. The impulses are given by the following equations:

y = 2 sin^2 x
y = 1 - sin x

Find all values of x, in degrees, for which the two impulses meet in the interval 0 degrees (is less than or equal to) x degrees < 360 degrees. [Only an algebraic solution will be accepted.]


And the answers are 30, 150, and 220 degrees. I would really appreciate any help or explanations!

2007-06-11 08:54:29 · 3 answers · asked by delilah 2

v/(1-v)?

2007-06-11 08:51:28 · 3 answers · asked by joefarmer 1

please show the step by step

2007-06-11 08:51:12 · 5 answers · asked by MaeMae 1

2007-06-11 08:48:40 · 7 answers · asked by disneyfreak 1

How do you simplify this?
Do you first divide 0.0067 with each term?

80,000 = [ 1 - (1.0067)^(-12 t) / 0.0067 ]

To make it clear, the first part in the brackets [ ] divided by 0.0067

I suppose you may have to use logarithms...

2007-06-11 08:48:38 · 2 answers · asked by jill b 1

possible equations to choose from ....



a. 4x + 2y - 3z - 5 = 0

b. 2x - y + 4z - 12 = 0

c. x + 3y - 2z + 5 = 0

d. 2x + 3y + 2z - 2 = 0

Or None Of These?

2007-06-11 08:46:55 · 4 answers · asked by Jake 1

possible solutions to choose from....



a. 3^1/2

b. (6^1/2)/3

c. 4(2^1/2)/3

d. 2(6^1/2)/3

e. 5^1/2

or none of these

2007-06-11 08:40:15 · 3 answers · asked by Doug 2

possible choices.....

a. x + y + z = 3

b. x - y + z = 3

c. x + y - z = 3

d. -x + y + z = 3

e. x - y + z = 1

f. x - y - z = 1

there is no such plane (only if a candidate exists but is not listed below)
or
There is such a plane but it is none of these

2007-06-11 08:36:52 · 4 answers · asked by Olivia 4

2007-06-11 08:32:03 · 4 answers · asked by Jimmy 1

2007-06-11 08:31:16 · 2 answers · asked by Doug 2

|x-4|>2

Can some one show me how to do this problem.

2007-06-11 08:29:25 · 4 answers · asked by christopher l 1

please type the step by step answer

2007-06-11 08:27:10 · 6 answers · asked by MaeMae 1

2007-06-11 08:23:42 · 2 answers · asked by Jake 1

y=(x-1/x)^x
y=x
What value is true for x and y (can you express it exactly?)?

2007-06-11 08:16:55 · 7 answers · asked by Anonymous

Solve each of the following systems by using either addition or substitution. If a unique solution does not exist, state whether the system is dependent or inconsistent.

10x+2y=7
y=-5x+3

Any help is much appreciated...

2007-06-11 08:11:31 · 5 answers · asked by Anonymous

2007-06-11 08:04:23 · 1 answers · asked by chris 2

2007-06-11 08:03:08 · 2 answers · asked by lilnessaslove 1

i need the best answer i not good at it and please explane

2007-06-11 08:02:57 · 10 answers · asked by joejoe611 1