Tuesday

July 29, 2014

July 29, 2014

Total # Posts: 17,557

**calculus**

If you draw this you see you want the integral from y =0 to y = 3 of -x dy y = ln(1-x) e^y = 1-x -x = e^y -1 so integral from 0 to 3 e^y dy - dy e^y - y at 3 = e^3-3 e^y - y at 0 = 1 so e^3 - 4 about 20 - 4 = 16

**pre-algebra**

when x increases by 2, y always decreases by 1 so m = slope = -1/2 y = -x/2 + b put in a point like (4,0) 0 = -4/2 + b so b = 2 so y = -x/2 + 2

**Math**

You are welcome.

**Math**

The top of the first rainbow will not fit into the bottom of the one above it.

**math**

tan 15 = d/495

**math**

You are welcome :)

**math**

yes -10 + 8 = -2 yes 9 - (-9) = 9+9 = 18

**Algebra where did I go wrong**

5! / [ 2! (5-2)! ] 5!/(2! 3!) 5 * 4 * 3 *2 /(2 * 3 * 2) 10

**math**

combine LIKE terms 8x + 6 x = 14 x 2 = 2 so 14 x + 2

**MATH**

You are welcome.

**MATH**

L * w = 225 2 L + 2 w = 60 so L + w = 30 and w = 30-L L (30-L) = 225 30 L - L^2 = 225 L^2 -30 L + 225 = 0 (L-15)(L-15) = 0 L = 15 meters

**SCIENCE HELP !!**

Do muskrats eat catfish? If so, they might get hungry.

**college calculus**

.5 = e^-k(5730) ln .5 = -.6931 = - 5730 k k = 1.2097*10^-4 .45 = e^-1.2097*10^-4 t ln .45 = -.7985 = -1.2097*10^-4 t t = 6601 years

**Algebra**

I can not. { x-[ -2 + sqrt(160) ]/6} * {x+[ -2 + sqrt(160) ]/6}

**History**

I guess I would go with Midway of the choices above. He certainly did not buy Alaska from Canada :)

**History**

seward's folly

**History**

Lots of things, including buying Alaska (Seward's Folly)from Russia :)

**algebra/ Can see I am right**

arrangements of three letters: 26^3 = 17576 but subtract 241 17335 times 1000 17,335,000

**Math please check my answers?**

237 (1.02)^t is correct

**Math please check my answers?**

slope = (83- -29) / (-2 - -10) = 112/8 = 14 which is indeed positive :)

**appliance repair**

Although E is the answer they are looking for, E is much more commonly used for the electric field strength which is Volts per meter. The question is poorly written.

**Algebra**

You are welcome. This is a good example to diiferentiate between combinations and permutations Combinations of 31 taken 5 at a time would be 31! /[ 5! (31-5)! ] That takes into account all the different groups of five you can make, but does not order the five for specific offi...

**Algebra**

It is not combinations because the order matters, it is permutations. (Joe could be either president or vice president for example and those are not the same) 31!/(31-5)! = 31!/26! = 31*30*29*28*27 = 20,389,320

**Evaluate the expression.Algebra**

9*6*3 /(6*4) 9*3/4 27/4

**geometry**

2 x + 10 = 80 2 x = 70 x = 35

**physics**

used up 67,500 + 290,000 - 30,000 Joules

**math 6 probaility**

there are four possible outcomes of flipping a pair h h h t t h t t so you should get h h 60/4 = 15 times we got it 24 or 9 more times than expected

**math 6 probability**

It is a whole new game after the first play. 75% IF you had said what is the probability of him hitting two in a row, that would be .75*.75 BUT that is NOT what you were asked.

**math**

up 4 in horizontal 10 so 4/10 = .4

**math**

do the others the same way

**math**

That was using the distributive property. You can also use FOIL if you know it.

**math**

4. (3x + 4)(x – 2) (1 point) 3x(x-2) + 4(x-2) 3 x^2 - 6 x + 4x - 8 3 x^2 -2x - 8

**math**

2 x * 10 x = 2*10 * x *x = 20 x^2 2. –3m(m + 8) = -3 m(m) + -3m(8) = -3m^2 - 24 m

**math 6 probability**

no, it hit the red section 225 times out of 1125 times spun

**math 6 probability**

5*225 = 1125

**History**

I guess you are talking about Canada maybe? Railways came after the revolution in the US. Was Canada several colonies so they could have inter-colonial railways?

**Algebra please check my answers**

4) The formula below can be used to find the amount of radioactive material that remains after a certain period of time, where A0 is the initial amount of material, A is the amount of material remaining after t hours, and k is the decay constant. A = A0(2.71)-kt !!!!!!!! =====...

**Algebra please check my answers**

3) Robert is considering purchasing a manufactured home that costs $77,300. If he expects the home value to decrease 8% each year, which function will show the value of Robert's manufactured home in t years? A. V(t) = $83,484t B. V(t) = $77,300(-0.92)t C. V(t) = $77,300(1....

**geometry**

6/15 = x/81

**Math**

band alone 11 choir alone 17 band and choir alone 4 band and math alone 7 math and choir alone 6 band choir and math 3 math alone 9 from 11+4+10+6+17 + M = 57 so 2 classes = 4+7+6 = 17

**Math 6 meters help**

144 = 2L + 2 w so L + w = 72 L = w + 4 so w + 4 + w = 72 2 w = 68 w = 34 then L = 38 A = L * w = 38 * 34 = 1292

**algebra**

not combinations because order does not matter in combinations we need permutations of 7 taken 4 at a time p(n,r) = n!/(n-r)! = 7!/3! = 7*6*5*4 = 840

**Algebra**

x intercept of f(x) = -3 y intercept of f(x) = 12 g(x) = -3 x -9 x intercept of g(x) = -3 y intercept of g(x) = -9 so it is not A

**HIS204**

By the way I agree with Stephen and with Ms. Sue. However I feel especially strongly about 4.4 since I lived in California during the war and friends of my family were included. http://www.history.com/this-day-in-history/war-relocation-authority-is-established-in-united-states

**HIS204**

4.4 !!!! Look up history of Japanese - Americans during WW2

**Math**

8*8 = 64 squares first piece has two possible spots so 2/64 is chance it will pick one of them now there are 63 spots left and the second piece has to hit it. 1/63 is that probability 2/64 * 1/63 = 4.96*10^-4 = .000496 ------------------------------- 8 rows first piece can hit...

**Math 6. Correct?**

You are welcome.

**Math 6. Correct?**

3/18 = 5/30 yes

**Math 6. Correct?**

30 feet = 360 inches 360/5 = 72 to 1 4.5 inches * 72 = 324 inches = 27 feet not 29.5

**trianom**

the minute hand does two complete circles distance around 2 circles = 2 * 2 pi r = 4 * pi * 9 = 113 inches

**Physics**

That link is to the commutator page. Go back one page in the link to see why the current in the armature electromagnet must be reversed every half turn.

**Physics**

reverses current in armature as the shaft turns so that torque is always in the same direction. http://electronics.howstuffworks.com/motor5.htm

**Civics**

I should hope D (I think you mean opinions, not options). However all too often we seem to get A

**u.s. history**

We entered WW1 toward the end of the war and the country was not nearly so involved in WW1 as in WW2. After WW1 tough, we were a major nation on the world stage because the arrival of American troops in France was crucial to the allied victory.

**u.s. history**

Well I see that Victory gardens and stamp ration books for example were used in both wars, but sorry, I do not know enough about WW1 in the USA to help.

**u.s. history**

Do you men WW1 or WW2 ???? Your answers apply to WW2 Not sure about WW1, was not there, but it was short for the USA (NOT for Europe !! ) and did not require the home front mobilization of WW2

**help please on this**

mutation see: https://answers.yahoo.com/question/index?qid=20120409133046AADHBVS

**Physics -- check answers please**

2, yes c 3. is D. You need a transformer and rectifier in the little box you plug in to the wall to charge your cell phone.

**Physics -- check answers please**

1. a If you look at a maritime chart you will see that true north is up toward the top of the page but magnetic north is a different direction, here about 17 degrees to the west for example.

**Math - Inequalities**

You are welcome :)

**Math - Inequalities**

a closed dot means included like x < 5 means less than (open) x </= 5 means less than or equal to (closed) http://mathcentral.uregina.ca/QQ/database/QQ.09.05/cynthia1.html

**math**

tan slope = 13/5 slope = tan^-1 (13/5) = 69 degrees

**Geography**

They were heavily involved in maritime trade with everyone from China to Egypt even long before Vasco de Gama opened the Indian Ocean and then the South China Sea to European traders and they tended to adopt the religions brought by the people they traded with. That includes H...

**math 6 rule pattern**

You are welcome.

**math 6 rule pattern**

except for 3 3 they are all multiply by 2, add 1 I bet 3 3 should be 3 7

**error at end**

t at top = 14/9.8 = 1.43 s total time in air = 2t = 2.86 s 20 = u (2.86) so u = 6.99 m/s so U = sqrt (6.99^2+14^2) = 15.64 m/s and tan theta = 14/6.99 theta = 63.5 degrees

**furthermathematics**

Initial vertical speed Vi = U sin theta constant horizontal speed = u = U cos theta horizontal problem 20 = U cos theta * T where T is time in air vertical problem v = Vi - g t v = 0 at the top so t at top = Vi/g g = 9.8 m/s^2 on earth so t at top = Vi/9.8 now at the top at 10...

**science help !!**

I am not sure. Although it is a new technology here and CA will have the first one in the uSA it is hardly groundbreaking in Japan for example. Money, legal challenges, mountains, obtaining rights of way...... http://www.sfbg.com/politics/2014/03/07/california-high-speed-rail-...

**Science Check Answer?**

You are welcome.

**Science Check Answer?**

https://www.google.com/search?q=larynx,+trachea,+bronchi,+pharynx,+alveoli&client=firefox-a&hs=wBE&rls=org.mozilla:en-US:official&channel=sb&tbm=isch&tbo=u&source=univ&sa=X&ei=fQJ9U9WkHcKLqAaC-ICgCw&ved=0CE0QsAQ&biw=1011&bih=620

**Math 6 gemoetery**

You are welcome :)

**Math 6 gemoetery**

LOL, well there is one sure way to find out 93 * 58 * 2.47 = 13,323.18 now 6000*1.5 = 9,000 6000*2 = 12,000 the last two are even lower

**science**

Yes

**science**

http://www.thefreedictionary.com/Selectively+permeable

**science**

you are selecting, which means choosing some and not others to let through

**science**

Oh come on, make a guess :)

**Algebra**

13-2 = 11 9-4 = 5 so 11 a + 5 b

**Science 1 question**

Yes, confusing.

**Science 1 question**

Yes, A

**Chemistry**

1 atm is about 1.013*10^5 Pa or 101.3 kPa 101.3 - 2.5 = 98.8

**Science Check Answers?**

alveolus has high surface area to allow lots of gas exchange

**English**

B I think yes C yes B

**Algebra 2**

x = 2 y = -1 sketch graph in Quadrant 4 if theta is angle below x axis sin theta = -1/2 csc theta = 1/sin theta = -2/1

**math**

x </= 5-2.25 x </= 2.75

**algebra**

y = 4 x + 1 y + 2 x = 13 so 4 x + 1 + 2 x = 13 6 x = 12 x = 2 then y = 4(2) + 1 = 9

**Algbera**

add or subtract a full circle (or several of them) 130 + 360 = 490 of course 130 is coterminal with 130 but hardly counts as an answer

**math**

sure enough, 20 months

**math**

total paid = 35 * number of months 700 = 35 * n so n = 700/35

**math**

t is the same for both I assume 65 t + 35 t = distance between LA and NYC t = distance/100 so distance from NYC = 35 * (distance between)/100

**Calculus**

Oh, if you mean the algebra look at the numerator [ x -(x+h)] = x - x - h = -h

**Calculus**

h is a small increase in x which is allowed to approach zero to get the slope of f(x) at x, the definition of the derivative Definition of deriviative of f(x) is: df/dx = {f(x+h) - f(x) ]/h as h-->0

**Calculus**

What do you want, the derivative? if so f(x) = 1/x f(x+h) = 1/(x+h) f(x+h)-f(x) = 1/(x+h) - 1/x = [ x -(x+h)] /[x(x+h)] = -h/ (x^2 + x h) [f(x+h)-f(x)]/h = -1/(x^2+xh) limit as h-->0 = -1/x^2 which is of course the derivative

**Algebra/Permutation**

in general for n items taken r at a time P(n,r) = n!/ (n-r)! for n = 4 and r at a time P(4,r) = 4!/(4-r)! so for 4 taken 1 at a time 4!/3! = 4*3*2*1/(3*2*1) = 4 or for 4 taken 2 at a time 4!/(2)! = 4*3 *2*1/2*1 = 12

**Algebra**

whoops, sorry, thanks !

**Algebra**

mean is 6 yes I get sqrt 80 = 8.94 for SD 2^2 + 2^2+1^2+6^2+3^2+3^2+1^2+4^2 4+4+1+36+9+9+1+16 = 80 sqrt 80 = 8.94

**Algebra**

That standard deviation is much too big. Are you sure it is not the variance and you forgot to take the square root?

**geometry**

You are welcome, good luck !

**geometry**

look at http://www.regentsprep.org/Regents/math/algtrig/ATT1/trigsix.htm you only really need sin, cos, tan for now.

**geometry**

ok, recipe for right triangle where hypotenuse is opposite right angle: sin of angle = opposite side/hypotenuse cos of angle = adjacent side / hypotenuse tan of angle = opposite side/adjacent side

**geometry**

Now Taylor, I told you to draw a picture. what is adjacent side, what is opposite side, what is hypotenuse?

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