Saturday

October 1, 2016
Total # Posts: 44,316

**Physics**

t is 2.5 Vi is 15 m/s up a = -9.8 m/s^2 up (or, 9.8 m/s^2 down) d = Vi * t + a/2 t^2 = 15*2.5 - 4.9 * 2.5^2 = 6.875 m Vf is Vi + at = 15 - 9.8 t^2 (though it does not matter for this question)

*September 22, 2016*

**Math**

x = 2 A = {2}

*September 22, 2016*

**Math - eh?**

{x: x 3x=6} ?? Do you mean {x: 3x=6} ?? Then you ask Does A? Does A what? However, you are correct in saying that {2} is not 2

*September 22, 2016*

**Computer science**

https://en.wikipedia.org/wiki/Virtual_memory

*September 22, 2016*

**math**

(72+84+90)/6 + 90/2 = 86

*September 22, 2016*

**math**

also check out the way the coefficients are sums of subsets of the roots: http://mathforum.org/library/drmath/view/61024.html

*September 22, 2016*

**Mathematics**

list a few how far apart is each from its neighbor?

*September 22, 2016*

**math**

think of the factors of 18 which two differ by 3?

*September 22, 2016*

**Algebra**

x = x/3 + 8 + 52

*September 22, 2016*

**Math**

(1 hr 54 sec) * 7 And yet, I suspect you meant 1 hr 54 min.

*September 22, 2016*

**Algebra**

900/(300+250) hours later

*September 22, 2016*

**Math**

6:8:15 * 7/5 = 42/5 : 56/5 : 21

*September 22, 2016*

**calculus**

x^2+y^2 = 10^2 so, when x=6, y=8 2x dx/dt + 2y dy/dt = 0 Now just plug in your values to find dx/dt

*September 22, 2016*

**math**

14250 * 1.02^3

*September 22, 2016*

**United States History**

thank you

*September 22, 2016*

**United States History**

How is this map different from a typical map of the United States? I couldn't get the map to paste here but it is of the Eastern United States with all the states names crossed out and Irish names put in. circa 1900's I think it was during the potato famine when Irish ...

*September 22, 2016*

**Math**

2P = 3*1000

*September 22, 2016*

**Math**

Since x:y = 7:9, y = 9x/7 (9/7)x = x+10

*September 22, 2016*

**Algebra**

d+t = 48 t+8 = 3(d+8) Now just solve for d and t.

*September 22, 2016*

**Math**

well, does it?

*September 22, 2016*

**Math**

well does it?

*September 22, 2016*

**Geometry**

just take each point and see whether the rule transforms it to the desired point. For example, (x,y+1) transforms (2,4) -> (2,5) Then see which rule takes all 3 points where you want them.

*September 22, 2016*

**Math**

Use the first pair to get the ratio 60/3 = 20 So, for each pair, the 2nd value should be 20 times the 1st value.

*September 21, 2016*

**AP physics**

their combined speed is 1560 km/hr time = distance/speed, so ...

*September 21, 2016*

**Math**

You asked: Determine the number of seats in a bus for each value of r. yet you did not provide any values of r. So, I picked one: 0 Now you pick some others and evaluate 5 + 4xr for each one. I like to help with answers, but don't make me come up with the questions, too.

*September 21, 2016*

**Math**

0: 5 ...

*September 21, 2016*

**algebra**

so far so good: 17/4x = 23/(x+6) now cross-multiply (shorthand for saying multiply by the LCD): 17(x+6) = 23(4x) 17x + 102 = 92x 102 = 75x x = 102/75 = 34/25

*September 21, 2016*

**Math algebra**

hint: think "difference of two squares"

*September 21, 2016*

**MATH HELP**

1C w/o the typo no ideas on the others?

*September 21, 2016*

**Math**

just write their areas as a ratio 24:15 or 8:5

*September 21, 2016*

**algebra**

all ok

*September 21, 2016*

**Math (Geometry)**

statement: if A then B converse: if B then A

*September 21, 2016*

**Math**

a/(1-r) = 100 ar = 24 divide and you have 1/(r(1-r)) = 100/24 r = 2/5 or 3/5 a = 60 or 40

*September 21, 2016*

**Math**

first step: list the possible combinations of coins: 4q, 0d, 1n ... 0q, 0d, 21n Then note how many cannot change $1.00

*September 21, 2016*

**Physics**

a = -45m/s / 9s = -5m/s^2 s = 45t - 5/2 t^2

*September 21, 2016*

**Math**

time to review your basic trig functions. The height h is found by h/100 = tan50°

*September 21, 2016*

**MATHEMATICS**

after t hours, the fraction left is (1/2)^(t/9) So, after 3 hours, there is (1/2)^(3/9) = .7937 of the original amount left.

*September 21, 2016*

**Math**

time = distance/speed, so (400/(150/20)-400/(100/12.5))(100/12.5) = 26.66m

*September 21, 2016*

**Math**

(400/(150/20)-400/(100/12.5))(100/12.5) = 26.66m

*September 21, 2016*

**MATH**

after t hours, the amount left is 2 * (1/2)^(t/5)

*September 21, 2016*

**jay**

nope. And where are your divide symbols? P/2 = l+w now go from there.

*September 21, 2016*

**Calculus**

I assume you want k and m so that g(x) is continuous? Just to make things easier, recall that e^(ln u) = u so, e^(ln(2x+3)) = 2x+3 If so, then you want the endpoints to match: (k(-2)^2)+m = 2(-2)+3 k(3)-m = 2(3)+3 or, 4k+m = -1 3k-m = 9 I guess you can handle that, yeah? As ...

*September 21, 2016*

**math**

20-4-4-4-4-4 = 0

*September 21, 2016*

**Physics**

8.0 m/s^2 * 1km/1000m * (3600s/hr)^2 = 103680 km/hr^2 after h hours, the distances must be the same: 91.0h = 52.0h + 51840h^2 h = 0.000752315 hours = 2.7 seconds Or, you may want to convert km/hr to m/s, but the answer is the same. To get the distance, just plug it into either...

*September 21, 2016*

**math**

well, 2.5 = root(6.25) now just order the squares.

*September 21, 2016*

**Math**

2m^2+m-2m = 2m^2-m = m(2m-1) I suspect a typo, as this does not fit well with the grouping techniques.

*September 21, 2016*

**Math**

I get 4502 counted using bash: for i in `seq 1 11521` ; do echo $i ; done | tr -c -d '3' | wc -c

*September 21, 2016*

**biomechanics**

how long does it take for v to drop to zero? v(t) = 14.27 - 1.67t using that t, the distance moved is s(t) = 14.27t - 0.835t^2

*September 21, 2016*

**Physics**

or, more directly, recalling that the range is R = v^2/g sin2θ just solve for v in v^2/9.8 * sin62° = 8.3

*September 21, 2016*

**Math**

you manage to use + and x, but can't manage / ? 18+9x(5+4)/3-5 18+9x9/3-5 18+81/3-5 18+27-5 ... or 18+9x(5+4)/3-5 18+9x(9/3)-5 18+9x3-5 18+27-5 ...

*September 21, 2016*

**trigonomentry**

not sure what you mean by a "series" of cos, but if you recall your binomial expansions, (a+b)^4 = a^4+4a^3b+a^2b^2+4ab^3+b^4 and then let a=1 and b=cos^2(x), you have sin^8(x) = (sin^2(x))^4 = (1-cos^2(x))^4 = 1 - 4cos^2(x) + 6cos^4(x) - 4cos^6(x) + cos^8(x)

*September 21, 2016*

**Algebra**

well, to get rid of all those words, and use some math, 2u^4*v^2 / 3u = 2u^3v^2/3 or, 2/3 u^3v^2

*September 21, 2016*

**Math**

or, you can think of it like this 27 = 9*3, so 7:9 = 7*3 : 9*3 = 21:27

*September 21, 2016*

**physics**

You need to use the velocity, since distance = speed * time The speed is -15 m/s, so after t seconds, starting from x=30, x = 30 - 15t So, you are correct that x(1) = 15, but after 2 seconds, x(2) = 30 - 15*2 = 0 The object has indeed moved 30m after 2 seconds, but it has ...

*September 21, 2016*

**Geometry H**

E does not matter for this question. Since D bisects the angle, m<CBD = 1/2 m<CBA = 36

*September 21, 2016*

**physics**

you can make this hard (or more general) by setting up distance/speed calculations, and all that, but just notice that the river's speed is 1/2 that of the boat. So, the boat goes downstream 1/2 as far as it goes across.

*September 21, 2016*

**Math :)**

since 120° is 1/3 of a circle, the other two values must add up to 2/3, or twice the 120° value: x+8 = 2(x+2)

*September 21, 2016*

**java programming**

you better learn to read your java documentation. Here's a discussion of the topic: http://stackoverflow.com/questions/17538182/getting-keyboard-input

*September 21, 2016*

**Maths**

you can do it that way, but how has that helped? How do you solve x^2 = 3-2x ?

*September 21, 2016*

**GOVT JUNIOR COLEGE**

or, in the spirit of one "l", when your parot has gone.

*September 21, 2016*

**math**

google "polygon" and you will find many discussions. Or, check your course text. Or, just look in a dictionary!

*September 21, 2016*

**Math - check answer**

Looks good to me. But lots of time science folks like to use natural logs and base-e exponentials. So, since log 1.264911064 = .23500 1.264911064 = e^.23500 So, your function becomes f(t) = 58000 e^.235t

*September 21, 2016*

**physical sciences**

In one second he moves 15m, leaving 35m for braking. The speed decreases from 15m/s to 0 in 3 seconds, meaning the acceleration a = -15/3 = -5 m/s^2 Now, the distance traveled will be s(t) = 15t - 5/2 t^2 So, is s(3) less than 35m?

*September 21, 2016*

**Math**

10b + 3g + .5y = 100 b+g+y = 100 There's no unique solution, but you can see that g = 20 - 19b/5 y = 80 + 14b/5 So, it is clear that b must be a multiple of 5. Now, if b=5, g = 20-19b/5 = 20-19 = 1 So, 5 blue, 1 green and 94 yellows works out fine. You can't have more ...

*September 21, 2016*

**Maths**

x + 2(2x-4) = 57

*September 21, 2016*

**Math**

oh, you can complicate it up a bit by using a proportion: x/3 = 4/1 but this one is in fact pretty simple.

*September 21, 2016*

**Math**

if the ratio is 4, then the similar figure has lengths 4 times as big as the original. 4*3 = 12

*September 21, 2016*

**8th grade math-exponents**

it's a lot easier without all those words: (x/2)^3 * (x/2)^4 ---------------------- ((x/2)^3)^2 = (x/2)^7 / (x/2)^6 = x/2 Hmmm. Not what you want. I suspect a typo somewhere.

*September 21, 2016*

**Math**

aha! That means that while sinx=4 is a "solution" to the polynomial, it is not a real solution. It is extraneous, due to the properties of sin(x)

*September 21, 2016*

**Math**

quadratics always work. Maybe it just doesn't factor easily. Nope. works just fine: (3sinx+1)(sinx-4) = 0 Now just evaluate sinx so you get solutions for x.

*September 21, 2016*

**Differential equations**

you can start by noting that if u = ln(5x/(x+3)) du/dx = 3/(x^2+3x) The rest should be not so hard now.

*September 21, 2016*

**Math**

can you say run-on sentence? Slow down and say what you want - that breathless jumble is giving me a headache!

*September 21, 2016*

**math**

First step: come up with a function you want to minimize. Can you describe the cost in terms of the quantities?

*September 21, 2016*

**Math**

Hmmm. Better go with Reiny. I thought my answer was a bit odd.

*September 21, 2016*

**Math**

15/2 √279

*September 21, 2016*

**Math**

If the change in longitude is θ radians, the WE distance is 6400θ km. Since time = distance/speed, then (assuming a constant speed), (6400θ + 4500)/950 = 11 θ = 0.9297 = 53.3° So, now you know how far East Q is from P. As for QR, 4500 = 6400θ so, ...

*September 21, 2016*

**Algebra 1**

It is used for exponents, but some rather strange people use it to mean ^2 or squared. Going on that assumption, we have 3[42-2 (10^2-9^2)] 3[42-2(100-81)] 3[42-2*19] ... If I got that wrong, TJ, fix it and carry on.

*September 21, 2016*

**College Algebra**

1/x + 1/(20-x) = 4/15

*September 20, 2016*

**Math**

use the usual distance formula: √(((a-3b)-(a+4b))^2 + (a-(a-b))^2) = √(-7b)^2+(b)^2) = √(50b^2) = 5b√2

*September 20, 2016*

**PreCalculus**

sorry about the time. I had to guess at the unasked question.

*September 20, 2016*

**PreCalculus**

it is 10:24 a.m.

*September 20, 2016*

**Math**

looks good to me

*September 20, 2016*

**Math**

well, how many ounces in 6 lbs? Divide that by 5oz/apple to get the no. of apples.

*September 20, 2016*

**6th Grade Maths**

45/(2 x 4.7 - 4.4) x 6 = 54

*September 20, 2016*

**Advanced Functions 12**

not sure what the secant lines mean. At x = 1/2, they all pass through 1/2 f(x) = (3 - 1/4)/2 = (1/2,11/8) That won't get anywhere near the tangent line, no matter what other point you choose. I suspect there is something left unsaid here.

*September 20, 2016*

**Math**

well, the list of running times is 5,7,8 can you not figure the range of such a list?

*September 20, 2016*

**calculus need help**

Really. Ha you know that the solution of y" + y = 0 is y = a sinx + b cosx Now use the method of variation of parameters: We now have y1 = sinx y2 = cosx The Wronskian of {sinx,cosx} is -1 u1 = ∫cosx tanx dx = ∫sinx = -cosx u2 = -∫sinx tanx dx = ∫...

*September 20, 2016*

**math**

cannot access files stored on your computer. duh.

*September 20, 2016*

**Math**

(1/3 ft)/ (1/6 yd) but, since 1 yd = 3 ft, you have = (1/3 ft) / (1/2 ft) = (1/3) / (1/2) = 2/3

*September 20, 2016*

**maths**

You have three unknowns, and only two equations. Here is what wolframalpha.com says: c+s+h = 100 5c + s/10 + 2h = 100 http://www.wolframalpha.com/input/?i=solve+c%2Bs%2Bh+%3D+100,+5c+%2B+s%2F10+%2B+2h+%3D+100 There is no unique solution, but if you play around, you can see ...

*September 20, 2016*

**algebra**

correct

*September 20, 2016*

**algebra**

what do you mean by "write a full" ? Note that as x grows by 1, y grows by 2. SO, start wity y = 2x Now adjust that so that the values agree with those in the table.

*September 20, 2016*

**Math**

5.25/.75 = ?

*September 20, 2016*

**Math**

Why have two variables? Each function has a flat fee and an hourly rate. The only variable is the time. You want the time to be such that the two cost are equal. Where did you get the 2? You're not multiplying by the number of service calls. Each service call has a flat ...

*September 20, 2016*

**Math**

well, st = u + v/2 now just one more step to go...

*September 20, 2016*

**math**

again? See your first post, or the related questions below

*September 20, 2016*

**Math**

if moving in the same direction as the bus, just add the speeds. If moving in the opposite direction, subtract her walking speed from the bus's speed.

*September 20, 2016*

**Math**

No. It grows 144/7 = 20.57 inches. Think about it. It takes 7 days to grow 6 inches. 24 is a little more than 3*7. So, it will grow a little more than 3*6 = 18 inches. You need to work on your reading, too...

*September 20, 2016*