Saturday

May 30, 2015

May 30, 2015

Total # Posts: 31,442

**Calculus**

just add the vectors. That is the resultant, call it r. The equilibrant is -r: that vector which cancels the resultant, keeping things in equilibrium.
*April 30, 2015*

**Calculus**

vectors are just a compact way of describing three independent sets of numbers. You just have 3a-6 = -3 9-2b = 1 6-2b = -2 clearly, a=1, and any value of b will work. since (1,3,2) and (3,b,b) are not collinear, they span R2.
*April 30, 2015*

**Math**

pq-pr-qp+qr-rp+rq or, arranging factors alphabetically, pq-pr-pq+qr-pr+qr -2pr+2qr 23ab-12ab - 12bc^2-13bc^2 11ab - 25bc^2
*April 30, 2015*

**Math**

just plug and chug: 2(-7/2)^2 - 9(-7/2) + 7 ...
*April 30, 2015*

**Math**

nothing to solve. just evaluate the expression 3(-1.3)(2/5) - |-1.3-2| -1.56 - |-3.3| -1.56 - 3.3 -4.86
*April 30, 2015*

**Math**

(3245.50-143.15)(1-0.10) = 2972.115
*April 30, 2015*

**Calculus**

dy/dx = (1+x)/xy y dy = (1+x)/x dx 1/2 y^2 = lnx + x + c since y(1) = -4, ln 1 + 1 + c = 8 c = 7 1/2 y^2 = lnx + x + 7 . . .
*April 30, 2015*

**math**

pi * 9^2 * 4
*April 30, 2015*

**math**

if the digits are a,b,c we see that a=4 Then we are doomed. If b and c are both odd, they cannot sum to 5, which is also odd. And how about a little punctuation? That run-on sentence is very annoying.
*April 30, 2015*

**Algebra 2**

Is there a question in there somewhere?
*April 30, 2015*

**math**

just subtract what was used from the original amount: 9100 - 321*28.286 However, that assumes that all the leftover parts could be combined to form new circles; not very likely. A better way to look at it is to decide how many rows and columns of discs could be cut. 130/6 = 21...
*April 30, 2015*

**SOLVE -MATH**

9C6 * 6C3
*April 30, 2015*

**physics**

we have, since the focal length is constant, 1/f = 1/20 + 1/x = 1/16 + 1/(x+2.7) Just solve for x, and then find f.
*April 30, 2015*

**Calculus**

good work. Confirm with the graphs at http://www.wolframalpha.com/input/?i=plot+x%5E2%2B3x%2B2%2C+y%3D3x%2B2+for+-1+%3C%3D+x+%3C%3D+1
*April 30, 2015*

**maths**

you have a common ratio, so p/-6 = -32/p p^2 = 192 ...
*April 30, 2015*

**math**

No, P(black) = 9/10 1 - 9/10 = 1/10 B is the odds of drawing a white, not the probability.
*April 30, 2015*

**Physics**

1A is 1C/s You have 73mC/9s = 8.11mA the net charge is not relevant here, since all we need is the number of Coulombs.
*April 30, 2015*

**MAT 142**

keeping all the measurements in yards, (15/3)(8/3)(8/36)($30)
*April 30, 2015*

**Math**

clearly you can drop the trailing zeros, getting 504/5940 both are even, so you can factor out 2 top and bottom: 252/2970 and again: 126/1485 now 3's: 42/495 and again: 14/165 That's as far as you can go. Or, you can factor both numbers. 5040 = 2^4 3^2 5 7 59400 = 2^3 ...
*April 30, 2015*

**Math**

(8*7)/2 - π/4*3^2
*April 30, 2015*

**math**

hmmm. None of the polynomials factors over the reals, so I don't see any help there. Looks like GCF=1 and LCM = (1+4x+4x^2-16x^4)(1+2x-8x^3-16x^4)(16x^4+4x^2+1) if x=-1 we have -17,-7,21 x=0 we have 1,1,1 x=1 we have -7,-21,21 x=2 we have -231,-315,273
*April 30, 2015*

**math - eh?**

what's with the .. ?
*April 30, 2015*

**Math**

first expand: 4x^3y+30x^2y-35xy^2-72x^2y+80xy^2-11xy^2 then combine: 4x^3y-42x^2y-34xy^2
*April 30, 2015*

**Math**

(4)(14)+(-1)(3)+(-6)(8) = 56-3-48 = 5 Pretty grim score, eh?
*April 29, 2015*

**English**

What do you do when the author can't be found? How do you cite the book? Would use just the title of the book or explain that the info is missing?
*April 29, 2015*

**English**

what should you do if you need to cite a book for which you don't know the author?
*April 29, 2015*

**Algebra 2**

multiply through by 8x and you have 2(x+2)-3(4) = x 2x+4-12 = x x = 8 check: 10/32 - 3/16 = (10-6)/32 = 4/32 = 1/8
*April 29, 2015*

**Math**

to be a perfect square, all its prime factors must be squared. Since 7 occurs an odd number of times, 7^2 cannot divide the number. So, no, it is not a perfect square. It is almost a perfect square, though, since 2^6 * 3^10 * 5^12 * 1^18 = (2^3 * 3^5 * 5^6)^2
*April 29, 2015*

**Math**

6789 = 3*31*73 since 3,31,73 all divide the first term, and 6,62,146 all divide the second term, 6789 divides both terms, and thus the sum as well.
*April 29, 2015*

**Math**

all the powers must be a multiple of 3. So, it is a perfect cube. It is (2^3 * 3^4 * 5^2 * 7)^3
*April 29, 2015*

**MATH**

d = 7n 10d = 650+5n 10(7n) = 650+5n 65n = 650 n=10 so, d=70
*April 29, 2015*

**Molar mass**

so, what steps did you follow? If you want help with your error, show your work...
*April 29, 2015*

**Mathematics**

just plug and chug: 148225 - x^2 = 578132.1225 - 406278.76 + 1274.8x - x^2 x = -18.535
*April 29, 2015*

**pressure**

PV=nRT Just plug in your numbers and solve for P.
*April 29, 2015*

**math**

440x220 with the 440' side parallel to the river. the related questions below provide steps for the solution.
*April 29, 2015*

**Math**

if it is a perfect square, all of its prime powers will be even. Since if you have (2^a 3^b 5^c ...)^2 all the exponents are doubled.
*April 29, 2015*

**math: fundamental counting principal**

12*10*7*5
*April 29, 2015*

**math; solve problem**

the simplest solution is 32.2*21/13.65
*April 29, 2015*

**Math**

The problem is poorly worded. Why don't you draw a diagram, and tell us what the relevant points of reference are?
*April 29, 2015*

**MATH; STANDARD DEVIATION**

you can plug in your numbers and play around with Z table stuff at http://davidmlane.com/hyperstat/z_table.html
*April 29, 2015*

**Algebra**

y=0 at x = -1 for x > -1, y is increasing
*April 29, 2015*

**Pressure**

PV=kT, so P/T is constant Figure the increase in T (as a factor), and apply that same factor to P to keep the ratio constant.
*April 29, 2015*

**Math Help**

what, you can't plug in values for n? a1 = 1(1^2-6) = 1(-5) = -5 a2 = 2(2^2-6) ... a1=14 a2 = (-2)(14) = -28 a3 = (-2)(-28) ...
*April 29, 2015*

**Math**

GCF=1 LCM=pq
*April 29, 2015*

**math**

3x2 + 3x5 = 6+15 = 21 8x3 = 18 So, he needs more canvas than he has. Or, you could line up the two desired pieces, and he needs one large piece 3x(2+5) = 3x7, but his piece is only 3x6.
*April 29, 2015*

**algebra NEED HELP**

√(x-5) is always positive. So, there is no solution √(2-7x) = 2x 2-7x = 4x^2 4x^2+7x-2 = 0 (x+2)(4x-1) = 0 so, x = -2 or x = 1/4 But since √(2-7x) is positive, x = -2 is an extraneous solution So, x = 1/4 is the only solution
*April 29, 2015*

**algebra**

since y=kx, y/x is constant. Thus, 14/21 = 7/x
*April 29, 2015*

**Calculus and Vectors**

the resultant is <900/√2,-900/√2 + 100> Now just find the speed and direction.
*April 29, 2015*

**Calculus**

They span R2 if they are independent. That is, the 2nd is not a multiple of the 1st. So, what do you think?
*April 29, 2015*

**Math help Steve?**

right on
*April 29, 2015*

**Math**

well, you need 3x+4 = 16 or 3x+4 = -16
*April 29, 2015*

**Last week Help Math**

now way to tell about the median and mode, but the mean is changed from (10*10000)/10 to (9*10000+20000)/10
*April 29, 2015*

**Calculus**

Draw a diagram of the forces. tanθ = 76/220
*April 29, 2015*

**Math (check answers)**

#1 Nope (C) is (x+3)(x-1)(x-5) You want (x+3)(x+1)(x-5) #2 Nope There are a total of 11 votes, so for is 7/11 = 64%
*April 29, 2015*

**Math help!**

If the vertical lines have length y, and the horizontal sides have length x, then 3y+2x = 270 and the total area is a = xy = x(270-2x)/3 = 90x - 2/3 x^2 This is just a parabola with vertex at (135/2,6075/2), so the total area is 6075/2. Since x=135/2, y=45 Since the inside ...
*April 29, 2015*

**Calculus-limits**

take derivatives top and bottom. The desired limit is the same as the limit of (cosx-0)/1 = cosx Now take the limit as x->a so, (b) is the answer.
*April 29, 2015*

**math**

is that 13 in high? Presumably the circular top has the same circumference as the cylinder.
*April 29, 2015*

**math**

(a+36d)/(a+20d) = 7/4 (a+64d)/(a+36d) = 7/4 3a=4d looks like there are many such sequences: a=12, d=9 T21 = 192 T37 = 336 T65 = 588
*April 29, 2015*

**Algebra**

the angle is x, where tan(x) = 2/(30*12)
*April 29, 2015*

**Mathh**

note that y grows by 3 when x grows by 1. That means you can start with y = 3x But since y(0)=1 instead of 3*0=0, y = 3x+1
*April 29, 2015*

**Calc 1**

If the triangle has side x, then the area a = ((11-3x)/4)^2 + √3/4 x^2 That's just a parabola. Its vertex will be the minimum area. For maximum, check to see which is greater: a(0) or a(11).
*April 28, 2015*

**math**

do you know how to calculate the length of a helix? The radius is 2/π, so we have x = 2/π cos θ y = 2/π sin θ z = 15/4π θ 0 <= θ <= 8*2π
*April 28, 2015*

**calculus**

dy/dx = y^2/x^3 dy/y^2 = dx/x^3 -1/y = -1/(2x^2)+c y = 2x^2/(1-cx^2) what's with all the verbal noise? You want to discuss y' = 2x√(1-y^2)? Just say so dy/√(1-y^2) = 2x dx arcsin(y) = x^2 + c y = sin(c+x^2)
*April 28, 2015*

**Geometry**

the front wheel makes 6/10 of a turn for every turn of the rear wheel. So, the pedals move (6/10)*2pi*7 inches during that time.
*April 28, 2015*

**math**

.5L/s * 3.7gal/L * 3600s/hr = ? gal/hr
*April 28, 2015*

**Calculus**

f(x) = ax^2 + 1/3 for x >= 1 bx - 10/3 for x < 1 so, we need f(1) to be consistent. That is, a + 1/3 = b - 10/3 we also need f'(1) to be consistent: 2a = b so, a + 1/3 = 2a - 10/3 a = 11/3 b = 22/3 a+b = 11
*April 28, 2015*

**Math help**

well, what is (3√2)^3 ?
*April 28, 2015*

**Calculus**

actually, I misspoke. You want p when h=8200, so p(8200) = 101.3 e^(-.000151*8200) You should have caught that typo...
*April 28, 2015*

**Calculus**

dp/dh = kp dp/p = k dh ln p = kh+c p = c*e^(kh) p(0)=101.3, so c=101.3 p(h) = 101.3 e^(kh) p(1000) = 87.1, so 101.3 e^(1000k) = 87.1 1000k = ln(87.1/101.3) k = -.000151 p(h) = 101.3 e^(-.000151h) so, now solve for h when p = 8200
*April 28, 2015*

**Calculus**

120 sin 25° think about it -- a horizontal force (0°) does no lifting, and an upward force (90°) is all lift.
*April 28, 2015*

**Physics - Half Life Question Check!!!**

The amount left after t billion years is (1/2)^(t/1.25) So, you want (1/2)^(t/1.25) = 0.77 t/1.25 log 0.5 = log 0.77 t = 1.25 log(0.77)/log(0.5) = 0.471 Looks like (B) to me.
*April 28, 2015*

**Geometry**

a = 1/4 √3 (36/3)^2
*April 28, 2015*

**Algebra Word Problem**

if there are x price increases, the revenue is (95-x)(100+x) That is just a parabola. Its vertex represents maximum revenue.
*April 28, 2015*

**Calculus**

your logic and your answer are correct.
*April 28, 2015*

**Calc**

wold that not be just the integral of C' from 3500 to 8500? Just use the power rule for each term.
*April 28, 2015*

**Calculus help??**

f(x) = ∫[0,x] 2πu du df/dx = 2πx you are correct. I suspect that those choices belong to a different problem, or that there is a misprint in this one.
*April 28, 2015*

**Calculus I**

The question is, how many can you sell at $10? Let's say it's 1000. Then if there are x price reductions, you can sell 1000+500x So, the revenue will be (1000+500x)(10-x) The cost is 3000+2(1000+500x) profit is revenue - cost. Use your real value instead of 1000, and ...
*April 28, 2015*

**Math Check**

both right
*April 28, 2015*

**Math Check**

Both look good to me.
*April 28, 2015*

**math**

the left side is also just a difference of two squares, so ((a-3)+(a-2))((a-3)-(a-2)) = (2a-5)(-1) so, you have 5-2a = 5 a = 0
*April 28, 2015*

**Math**

it's a problem in exponential growth similar ones in exponential decay are things like radiocarbon dating, where the amount of carbon-14 diminishes each year by a certain small percentage.
*April 28, 2015*

**Math**

after t minutes, there are 2^(t/15) bacteria. So, find t when 2^(t/15) = 10000 t/15 log2 = log10000 t = 15 * (log10000/log2)
*April 28, 2015*

**math**

if the side of the base is s, then you know that 10s^2 = 810 The total area is the base (x^2) and 4 sides, each of area 10x.
*April 28, 2015*

**math**

the base is 18*18 each side is a triangle of base 18 and height 12, so the faces have area 4*(18*12/2) SO, just do the math.
*April 28, 2015*

**Algebra**

3x = 7*8/21 x+2 = 5*20/10 That should get you started
*April 28, 2015*

**math**

v = Bh so, 9B = 2025
*April 28, 2015*

**chemistry**

You Can Get Your All Chemistry and other subjects questions Solved just Visit: http://www.myassignmenthelp.net/data-structure-assignment-help.php
*April 28, 2015*

**5th grade (math)**

the difference between two numbers is found by subtraction: 13 1/10 - 12 1/2 = 12 11/10 - 12 5/10 = 6/10 or 3/5
*April 28, 2015*

**math**

v = 40mm * 25mm * 2mm = 2000 mm^3 so, the weight is 2000 mm^3 * .0005oz/1mm^3 = 1oz
*April 28, 2015*

**English**

In Edgar Allan Poe’s poem “The Bells,” how does the tone change from the beginning to the end? from melancholic to scary from cheerful to sinister from peaceful to frenetic from hopeful to embittered
*April 28, 2015*

**English**

"The Cask of Amontillado" Poe's use of a(n) _________________ narrator to tell the story heightens the uncertainty and sense of horror felt by the reader.
*April 27, 2015*

**College Algebra**

well of course the vertex is the maximum area. The parabola represents the area, right? And you are correct in your final answers, with the exception that when x=200 and y=125, 4xy = 4*200*125 = 100,000
*April 27, 2015*

**College Algebra**

well, if each pen is x by y, then the vertical lines have length x, and the horizontal lines have length 4y, then we know 5x+8y = 2000 then the area is a = 4xy = 4x(2000-5x)/8 = 1000x - 5/2 x^2 This just a parabola, and its vertex will be the maximum area. Work it out, and you...
*April 27, 2015*

**Math**

sums are terms separated by + or - signs products consist of two or more factors multiplied. So, what do you say?
*April 27, 2015*

**math**

then
*April 27, 2015*

**Inequalities Interval Notation**

After you get a bit of practice with this kind of stuff, you can feel confident using what you know about the graphs of polynomials. (2 + x)(5 + x)(4 - x) < 0 You know this is a cubic, with three roots. The graph crosses the x-axis at each root. So, pick a very large ...
*April 27, 2015*

**Math help!**

of course the are will be minimum if the width of length is zero. But that's not what you want, I'm sure. So, you want the arrangement of fences which will produce the maximum area. You don't say how the area is to be divided. Is the beet garden enclosed by the ...
*April 27, 2015*

**science**

Try To find Your Answers at below Link http://www.myassignmenthelp.net/chemistry-assignment-help.php
*April 27, 2015*

**math**

#1-3 are very poorly worded. Whoever phrased them like that ought to be shot. #1 x and y have equal rates of change #2 y has the greater rate of change. #3 clearly y changes faster. Heck, they told you that in just so many words. #4 ok #5 you gave the values for y=x^2 But the ...
*April 27, 2015*

**C++ Programming**

why don't you google C++ and some of those key concepts? You will find many code snippets illustrating the syntax.
*April 27, 2015*