Science & Mathematics - 3 October 2007

2007-10-03 16:39:17 · 4 answers · asked by Anonymous in Mathematics

Problem: √(x+2)-x=0, Note: x+2 is in the square root, -x isn't.
I added x to the right hand column, then squared both √(x-2) and x to get rid of the square root.

This gave me: x+2=x²
I subtracted x and subtracted 2 to get: 0=x²-x-2
I factored to get 0=(x-2)(x+1)
This gave x=2, x=-1

When I redistribute 2 and -1 into the equation -1 doesn't work, but 2 does, so x=2. Is this the final solution?

2007-10-03 16:38:36 · 4 answers · asked by Bluefast 3 in Mathematics

Say m is in grams, c is in metres per second, what unit will e be in.

2007-10-03 16:37:42 · 14 answers · asked by Allen 1 in Astronomy & Space

What's wrong with the weather (these past weeks) in places such as Seattle, Vancouver, Portland?

2007-10-03 16:36:26 · 4 answers · asked by lollerskates 2 in Weather

ive done these problems like 6 times and keep getting the same answers but they don't work when i check them. please help me...

7y - 2(y - 4) = 8y - (4y + 13)

= 7y - 2y + 8 = 8y - 4y -13
= 5y + 8 = 4y - 13
= 5y - 4y = -13 - 8
= y = -21

------------------

-6 + 10y + 18 = 4(2y - 6) - 8

= 10y + 12 = 8y -24 -8
= 10y + 12 = 8y - 32
= 10y - 8y = -32 - 12
= 2y = -44
= y = -22


(But when I go to check them, the variables dont work please help me and tell me what i am doing wrong)

2007-10-03 16:34:29 · 4 answers · asked by Anonymous in Mathematics

(a). height of ballon at the end of 39 sec?
(b).Average velocity between t=0 and t=39?
(c).velocity of ballon at end of 39 sec?

2007-10-03 16:32:25 · 1 answers · asked by Anonymous in Physics

A Creationist friend of mine has agreed to read a book of my choosing about evolution.

What is the best book I can give to my Creationist friend to get him thinking about the validity of evolution by natural selection?

2007-10-03 16:31:46 · 2 answers · asked by bokonon1000 1 in Other - Science

A=
2 -1 (is matrix)
3 6

a) write A as a product of elementary matrices.

b) use your result for a) to write A^-1 as a product of elementary matrices.

c) AB=
-3 5
1 2

solve for B?

2007-10-03 16:30:28 · 2 answers · asked by john m 1 in Mathematics

A. y=x-2
B. y=x+2
C. y=2x-1
D. y=2-x

2007-10-03 16:30:18 · 12 answers · asked by pkbrauer 1 in Mathematics

Hot always beats cold? I say no. because fire goes out with the right equipment. But again, fire melts ice. SO, who wins in
t he ultmate battle?

2007-10-03 16:27:25 · 11 answers · asked by dino_dan_94 1 in Weather

A.They have the same number of sides.

B.The total degree measure of the interior angles of each polygon is the same.

C.They have the same number of interior angles.

D. Their perimeters are equal.

2007-10-03 16:26:02 · 3 answers · asked by pkbrauer 1 in Mathematics

Im having a math block. Can anyone please help me? I know this is so easy.

2007-10-03 16:24:24 · 11 answers · asked by Anonymous in Mathematics

company manufacturing x surfsboards a day:
(a)what is the rate of chang fo total cost when the level of production is 10 surfsboard a day?

2007-10-03 16:20:57 · 2 answers · asked by Anonymous in Mathematics

The question was does the integral of dx/(x^2+3x+2) from 0 to infinity converge or diverge, and if it converges what does it converge to.
I did the integral and all the work and came to:
limit as b approaches infinity of [ln(b+1)-ln(b+2)]-[ln1-ln2].
The correct answer is it converges to ln2. I can see how that answer is produced, the ln of infinity must come to a small number, and ln1 is zero leaving just a positive ln2. But how do I know that the ln(infinity) converges instead of diverges?

2007-10-03 16:17:13 · 4 answers · asked by rman1201 4 in Mathematics

2007-10-03 16:16:46 · 4 answers · asked by donlm47@sbcglobal.net 1 in Botany

2007-10-03 16:12:01 · 12 answers · asked by Anonymous in Mathematics

2007-10-03 16:11:09 · 2 answers · asked by rhynx 1 in Physics

In the sense that they will crack/break easily.

2007-10-03 16:09:42 · 7 answers · asked by Brooksie 4 in Earth Sciences & Geology

what real value of x do the following vectors form a linearly dependent set in R3:

v1=(x, 1/2, 1/2), v2=(1/2, x, 1/2), v3=(1/2, 1/2, x)

my guess is that x can only be 1/2 because if you put the above vectors as the column of a matrix, say A, then u would try to see if Ax=0 would have nontrivial solutions (which means you should get a row of 0s when u row reduce the matrix, therefore i know 1/2 will definitely work). but is there any other number that will work ? if so how did u go about solving this (kind of) problem?

2007-10-03 16:07:32 · 1 answers · asked by Chris L 1 in Mathematics

2007-10-03 16:07:05 · 1 answers · asked by Anonymous in Mathematics

A 0.700 kg ball is on the end of a rope that is 2.00 m in length. The ball and rope are attached to a pole and the entire apparatus, including the pole, rotates about the pole's symmetry axis. The rope makes an angle of 70.0° with respect to the vertical as shown. What is the tangential speed of the ball?

I have a picture of this situation if you need it and I can email it to you if you let me know.

Thank you so much for any help. This is the only problem left that I just can't figure out.

2007-10-03 16:04:37 · 2 answers · asked by Physics 1 in Physics

for the 3x3 matrix ( ";" represents the end of a row)
[c,1,0; 1,c,1; 0,1,c], find all values of c, if any, that would make the matrix invertible. okay my own guess here c is anything but 0 (since 0 will make the first and second row identical, thus creating a all 0 row when u row reduce which means it's not invertible because u cannot obtain the identity matrix by row reducing) I suppose my real quesiton is the way to approach these types of problem in general. My thought is that any number that will create a 0 row when row reduce will obviously be excluded, but am I right in assuming that every other number will work therefore? or is there some other cases i need to look into?

2007-10-03 15:59:59 · 2 answers · asked by Chris L 1 in Mathematics

I am a senior in highschool and im thinking about what i want to major in.
My ultimate career choice is medicine. I'd like to do really good durring my undergrad get a good score on my mcats and get into med school. God forbid, if this doesn't happen I dont want to get stuck sitting in a lab for the rest of my life with a degree in bio.
I've narrowed down my second career pathway to Physical Therapy...I learned that the prephysical therapy requirments are almost the same as the ones for premed so if for any reason med school didn't work out I would probably only be taking 1 or 2 extra courses and that wouldnt waste too much time.
So, because my ultimate goal is to become a doctor but the reality is that not everyone makes it...is choosing kinesiology or movement sciences as my major a bad idea? I know that healthcare is what interests me however I dont want to major in biology or chemistry or physics. Everyone says that med school looks for a diversity of majors.
What should i do?!

2007-10-03 15:59:39 · 4 answers · asked by bubblicious fun 1 in Medicine

An oxygen molecule travels 975 miles per hour at room temperature. What is the velocity in meters per second?
10 pts to best first answer!

2007-10-03 15:57:44 · 5 answers · asked by Help312 2 in Chemistry

2007-10-03 15:57:17 · 3 answers · asked by AnonymousOne 2 in Earth Sciences & Geology

2007-10-03 15:57:16 · 9 answers · asked by ruas slickyboy 2 in Mathematics

Water is added to 4.267 grams of UF6. The only products are 3.730 grams of a solid containing only uranium, oxygen and flourine and 0.970 grams of a gas. The gas is 95.0% flourine, and the remainder is hydrogen.

A. From this data determine the empirical formula of the gas
B. What fraction of the fluorine of the original compound is in the solid, and what fraction in the gas after the reaction.
C. Whta is the formula of the solid product.
D. Write a balance equation for the reaction between UF6 and H20. Assume the empirical formula of the gas is the true formula.

2007-10-03 15:56:47 · 2 answers · asked by Mizan S 1 in Chemistry

3 questions in one
why does a needle float on water

why does the needle sink after soap is added to the water

2007-10-03 15:55:42 · 7 answers · asked by Ryan M 1 in Biology

I asked this a few days ago but couldn't get enough info on it. I know this is kind of a sick question but theres no help for it.

I'm writing a psychological horror and I need to know if the intestines in a human body can be strong enough to make a makeshift rope with? And in my book I haven't enough time to dry them out as others have suggested.

Only serious answers please!

2007-10-03 15:55:32 · 5 answers · asked by caiforniapoppy 3 in Biology

Simplify. Write answers in the form a + bi, where a and b are real numbers.
(8 + 2i)(4 - 9i)
a =
b =

Simplify. Write answers in the form a + bi, where a and b are real numbers.
(3 - 4i)(3 + 4i)
a =
b =

Simplify. Write answers in the form a + bi, where a and b are real numbers.
(-3 + 4i)2
a =
b =

Simplify. Write answers in the form a + bi, where a and b are real numbers.
-1/6-9i
a =
b =

2007-10-03 15:54:59 · 4 answers · asked by mir d 1 in Mathematics