Mathematics - 13 December 2007

5 *y square +13y-6>0

2007-12-13 06:20:07 · 2 answers · asked by Natalie S 1

Strontium-90 has a half-life of 28 years. Determine how much time has elapsed if the following fraction of a strontium-90 sample remains.
a) 1/4

b) 1/8

c)1/32

2007-12-13 06:09:42 · 1 answers · asked by Anonymous

sq= the square foot sign
1) sq of 200
a) 10 sq of2 b) 2 sq of100 c) 2 sq of 25
2)5 sq of20 - 6 sq of32
a)10 sq of2 - 12 sq of13 b)10 sq of5 - 6sq of2 c)10sq of5 - 24sq of2
3)There are 40 dimes and quarters in a drawer. Peggy counts them and determines their value to be $4.75. How many coins of each type are there?
a)6 quarters and 34 dimes b)10 quarters and 30 dimes c)5 quarters and 35 dimes
4)The sum of two numbers is 72. The difference of the numbers is 26. What are the numbers?
a)46 and 26 b)51 and 21 c)49 and 23
5)4k - kxy + 4pc - pcxy
a)(4 + xy)(k - pc) b)(4 - xy)(k + pc) c)(8 + xy)(k - pc)

2007-12-13 06:05:24 · 3 answers · asked by Michael T 1

A farmer plans to fence a rectangular pasture adjacent to a river. The pasture must contain 180,000 sq meters in order to provide enough grass for the herd. What dimensions would require the least amount of fencing if no fencing is needed along the river.

2007-12-13 05:57:51 · 3 answers · asked by Anonymous

,(0, ), (-1/3, ) I am lost

2007-12-13 05:57:04 · 5 answers · asked by blondie42 1

Find the length and width of a rectangle that has the given area and a minimum perimeter.

1. Area: 64 sq ft
2. Area: A sq. cm

2007-12-13 05:55:57 · 3 answers · asked by Anonymous

Evaluate ∫sinx/(1+x^2)dx?
∫sinx/(1+x^2)dx
u = arctanx
du = 1/(1+x^2)dx
x = tanu
sinx=sin(tanu)
evaluate ∫sin(tanu)du
u = cosx
du = -sinx dx
cant get further

2007-12-13 05:44:00 · 2 answers · asked by Namu 2

The volume V of such a hollow cylinder is given by
the formula V = π (R^2 −r ^2 )h . Find the volume of
such a cylinder in cm3, given that its external
radius, thickness (R - r) and height are 7.4cm,
1.3cm and 12 cm respectively.

How can I type this in the matlab???
thanx

2007-12-13 05:33:36 · 2 answers · asked by Lou M 1

solve the equation

2007-12-13 05:32:12 · 5 answers · asked by Anonymous

A scientific simple answer please

2007-12-13 05:29:43 · 8 answers · asked by farawaysofar 2

2007-12-13 05:28:51 · 7 answers · asked by Anonymous

A page is to contain 30 square inches of print. The margins on each side are 1 inch. Find the dimensions of the page such that the least amount of paper is used.

2007-12-13 05:27:21 · 1 answers · asked by Anonymous

2007-12-13 05:25:38 · 20 answers · asked by desiree 1

use the formula s=16t^2

where do you put in the height?

2007-12-13 05:22:05 · 6 answers · asked by Anonymous

What is the derivative of
f(x) = x(2x+1)^2 ?

2007-12-13 05:20:16 · 2 answers · asked by Anonymous

can someone help me solve this inequality. I did it, but I dont think I did it right?

x^2 - 6x -2 < x - 8

thanks!

2007-12-13 05:17:34 · 8 answers · asked by Fuzzyglasses 3

alright, i understand that by drawing 2 right angle triangles in the first and second quadrants, with the sides labelled (a), (b), and (root of all a^2 + b^2) i can prove that
sin (pi / 2 + theta) = cos theta...........but now
using the same method, i need to prove that
csc (180 degrees + theta) = - csc theta

i dont understand how this is proven because everytime i draw my diagram, it doesnt work...


or how do i prove that
sin (pi - theta) = sin theta????

thanks in advance... i missed 2 days of classes and im so confused!

2007-12-13 05:00:59 · 3 answers · asked by Anonymous

2007-12-13 04:59:01 · 5 answers · asked by jessi 1

why is xSin(1/x) same thing as sin(1/x) / (1/x) ?

2007-12-13 04:43:51 · 6 answers · asked by Anonymous

3^2 = 2 x 3+ 2 x 1+1
Using this expression, how could n^2 be expressed?

So far I have n^2=(n - 1) x n + (n-1) x (n-2) + (n-2) but I don't think it is correct. Help please?

2007-12-13 04:40:45 · 5 answers · asked by princessangel_janine 1

b)16^y = 64^2y - 1

c)36^t-2 = 216^-2t

d)8^2x-1 = 16^x-1

Thank you

2007-12-13 04:38:04 · 1 answers · asked by Anonymous

I was just wondering,Im so rubbish a Maths lol

2007-12-13 04:37:41 · 23 answers · asked by Giggles! 4

simplify: -10x - 3(x - 2) I got -13x - 6 Is that right?

Simplify: 6(y - 1) + 3 ( - 2y + 2) I got 0 is that right?

I'm stuck on solving

81 > - 9w

m/3 > - 9

p + 7 ≤ - 11

2007-12-13 04:26:47 · 6 answers · asked by Anonymous

If a <=-1, then, we can show a_n --> -oo
If a >= 0, this is a sequence of Riemann sums of f(x) = x^a over [0,1] and a_n --> Integral [0 to 1] x^a dx = = (x^(a +1))/(a +1) [ o to 1] = 1/(a +1)

My question is, what happens when a is in (-1, 0)? Then, this is not a sequence of Riemann sums over [0,1] because x^a is not defined at x = 0 when a < 0. It sems the limit is still 1/(a +1), but is this true?

2007-12-13 04:25:55 · 2 answers · asked by Anonymous

data is a set of eight binary digits, (eight bits) for example 10111011. A coding scheme called parity can be used to detect errors, however, parity can only detect an odd number of bit errors. Assume that each bit is in error with probability p, and that bit errors are independent. What is the probability that a transmitted byte (8 bits) will contain an undetected error?

2007-12-13 04:24:29 · 4 answers · asked by kondiii 1

2007-12-13 04:04:44 · 1 answers · asked by Anonymous

1) Find two numbers whose sum is 9 if the product of one by the square of the other is a maximum.

2)The sum of the bases and the altitude of a trapezoid is 36 inches longer than the other. Find all three dimensions if the area is a maximum.

3)Find the shortest distance from the curve (y² = x³) to the point (8,0).

Please help me.. I can't really solve it..

2007-12-13 04:01:34 · 1 answers · asked by shebi 1

Olive Math is standing on the 102nd floor of the Empire State building, thinking about mathamatics. She realizes that, if she were able to throw a ball from her present position, the height of the ball in feet, h, at time t seconds could be modeled by the equation
h = -16t^2 + 64t + 1224.

How high above the ground is the 102nd floor?
What is the greatest height that ball would reach?
How long would it take to reach that height?
How long would it take the ball to hit the ground?

Please help?? PLease just help me get started, im just really confused.

2007-12-13 04:01:04 · 8 answers · asked by Fuzzyglasses 3

We can reframe the question : A die is rolled untill 6 point is found.
What are the chances of getting 1 point in x number of attempts?
if x=1 the answer is 1/6
what are the values for x=2 ,3, 4 ....?

In the original question the if 1 is found the result is known as 6 will be definitely found at infinity.

2007-12-13 03:57:07 · 1 answers · asked by Marissa B 1

I need to understand how to figure this out myself. Please and thank you. Oh, and I give good points, so please help me. :)

"Problem 1": A, B, and C are points on a line with AB = 8.4 inches and BC = 2.9 inches. What is the length of AC if: B is between A and C?

5: For the segment in Problem 1, which equation expresses the relationship of AC to AB and BC?
AC = AB - BC

AC = BC - AB

AC = AB + BC

2007-12-13 03:56:42 · 8 answers · asked by Kirkylee 3