Mathematics - 1 November 2007

our assignment was give 10 best proved trigonometric identities. and our teacher said that it must be an above normal trig identity that is already proven...

what websites can you recommend? or if anyone can help me prove this:
2tanx/1-tan(pow2)x + 1/2cos(pow2)x-1 = cosx+sinx/cosx-sinx

thanks!!

2007-11-01 18:04:51 · 1 answers · asked by AeXanzzZ_gurL 2

Hi. I need help with math homework.
Question is:
1.Is 14,949 a reasonable answer for 3 x 4,983? Estimate a finding range.
2. Is 6,704 a reasonable answer for 856 x 9?
Estimate a finding range.
Pls help,
Thanks again

2007-11-01 17:55:51 · 2 answers · asked by havequestion 1

can some body help me?
the question is
i is a zero of y= x^4 -4x³ + 2x² -4x + 1
list all the zeros?

please explain . any help is appreciated. thnx~! ^-^

2007-11-01 17:52:04 · 2 answers · asked by John 1

A rectangular garden next to a building is to be fenced on three sides. Fencing for the side parallel to the building costs $40 per foot, and material for the other two sides costs $40 per foot. If $2200 is to be spent on fencing, what are the dimensions of the garden with the largest possible area?

The parallel side =?
The other two sides =?

2007-11-01 17:48:27 · 2 answers · asked by Anonymous

The sum of the height h and the base b of a triangle is 58. What height and base will produce a triangle of maximum area?

h=?
b=?

2007-11-01 17:44:34 · 4 answers · asked by Anonymous

The airspeed of a plane is 420km/h and its heading is 140 degrees. A wind of 40km/h is blowing on a bearing of 40 degrees. Determine the plane's resultant speed relative to the ground and the bearing of its true course.

2007-11-01 17:38:50 · 2 answers · asked by o0griff0o 2

if f(x)= e^2x - 5e^x + 6=0 has 2 solutions,
what is the smaller solution?
what is the larger solution?

2007-11-01 17:32:08 · 5 answers · asked by Anonymous

Suppose you contribute $70 per month into a fund that earns 6.15% annual interest. What is the value of your investment after 22 years?

2007-11-01 17:26:05 · 8 answers · asked by QT Patuty 2

i know that it has 1 and 100 0's after it but i dont know how to put it into scientific notation i think its 10 x 100 but im not sure

2007-11-01 17:18:38 · 3 answers · asked by Natedogg 1

2007-11-01 17:17:32 · 6 answers · asked by Anonymous

A 10*10 cm square card is folded, a circle with radius 1 cm is placed so that it is entirely on the square. If the upper square is marked yellow, the lower part is marked red. What is the probability that the circle lies entirely in the red part?

2007-11-01 17:09:08 · 4 answers · asked by Anonymous

2007-11-01 17:06:31 · 1 answers · asked by anna k 1

This is a particle motion problem. A point moves smoothly along the curve y=x^(3/2) in the first quadrant in such a way that its distance from the origin increases at the constant rate of 11 units per second. Find dx/dt when x=3.
This is a Calculus problem. The answer is dx/dt=4 units/second. I want you to explain the answer. Thank you so much. I appreciated it.

2007-11-01 17:03:59 · 2 answers · asked by Anonymous

Solve. x^2 – 7x – 4 = 0

2007-11-01 17:01:04 · 3 answers · asked by Anonymous

Solve by using the quadratic formula. x^2 = 5x + 8

2007-11-01 16:59:45 · 10 answers · asked by Anonymous

Simplify 8+√24/2

2007-11-01 16:58:39 · 7 answers · asked by Anonymous

So in class we had a pyramid of reeses and we need to find and equation for the number of candies in each row?and an equation for the sum of all the candies? the pyramid has 1 on the first row, 3 on the second, 6 on the 3rd and so on...we found out there is 220 candies in 10 layers. anyone?

2007-11-01 16:49:39 · 2 answers · asked by am 2

2007-11-01 16:46:57 · 4 answers · asked by Anonymous

2007-11-01 16:42:42 · 1 answers · asked by djvo3djvo 1

At noon a private plane left Austin for Los Angeles, 2100 km away, flying at 500km/h. One hour later a jet left Los Angeles for Austin at 700 km/h. At what time did they pass each other
please show work...

2007-11-01 16:33:14 · 9 answers · asked by littlepeculiar13 2

Look this is a 7th grade problem. B=3s^2t. Solve for t.

2007-11-01 16:32:55 · 5 answers · asked by unni a 1

Sketch a graph of a relation that is not a function and that has all real numbers in its domain and all real numbers less than or equal to -3 in its range.

2007-11-01 16:30:57 · 5 answers · asked by Admire 1

You have a bag of cubical balloons that you inflate at a rate of 40cm^3 per second, how fast will the balloon's surface area get larger when the balloons edges are 4cm long?

I have trouble solving things implicitly so any help on this would be appreciated.

2007-11-01 16:29:33 · 1 answers · asked by John Avry 2

how do i solve this.

2007-11-01 16:15:22 · 2 answers · asked by xOx Frenchie xOx 2

Bob will rent a car for the weekend. He can choose one of two payment plans. The first plan costs $53.98 for two days plus 13 cents per mile. The second plan costs $45.98 for two days plus 18 cents per mile. How many miles does Bob need to drive for the two plans to cost the same?

2007-11-01 16:15:13 · 13 answers · asked by Ash 2

I'm supposed to show that (C(x))² + (S(x))² = 1

C(x) = ∑ (from k = 0 to infinity) { [ (-1)^k] / (2k)! } x^(2k)

S(x) = ∑ (from k = 0 to infinity) { [ (-1)^k] / (2k+1)! } x^(2k+1)

I'm not allowed to just say C(x) = cos x and S(x) = sin x so cos²x + sin²x = 1

I was given a hint to let f(x) = (C(x))² + (S(x))² and I have already proven that f ' (x) = 0, so I know that f(x) is equal to some constant, but how do I show that constant is 1?

2007-11-01 16:14:53 · 1 answers · asked by q_midori 4

1. Steve traveled 200 miles at a certain speed. Had he gone 10mph faster, the trip would have taken 1 hour less. Find the speed of his vehicle.

2.The Hudson River flows at a rate of 3 miles per hour. A patrol boat travels 60 miles upriver, and returns in a total time of 9 hours. What is the speed of the boat in still water?


3. A designer attempts to arrange the characters of his artwork in the form of a square grid with equal numbers of rows and columns, but finds that 24 characters are left out. When he tries to add one more row and column, he finds that he has 25 too few characters. Find the number of characters used by the designer.

use the discriminant to determine the number of solutions of the quadratic equation, and whether the solutions are real or complex.
1. (3)1/2y2 - 4y - 7(3)1/2 = 0

2007-11-01 16:13:51 · 3 answers · asked by Snoopy Baby 1

can you help me find the intercepts?

1.) y = -x^2 + 9

2.) y= x^2 -9

2007-11-01 16:10:12 · 4 answers · asked by Juan C 6

Factor. 50x^3 – 90x^2

2007-11-01 16:09:38 · 5 answers · asked by Anonymous

Sorry to ask such a question, but our study group is at a loss as how to continue and our homework is due tomorrow. So here goes:

In order to receive credit we MUST use calculus techniques:

We have a piece of wire that is 100cm long and we're going to cut it into two pieces. One piece will be bent into a square and the other will be bent into a circle. Determine where the wire should be cut so that the enclosed areas will be at maximum. Note that it is possible to have the whole piece of wire go either to the square or to the circle

2007-11-01 16:08:34 · 3 answers · asked by pyrojelli 2