Monday

July 6, 2015

July 6, 2015

Total # Posts: 32,126

**Math**

m = -2
*April 22, 2015*

**math**

If there were a adults, there were (440-a) children. So, the money collected. 42a + 18(440-a) = 12264
*April 22, 2015*

**Math**

given the various dimensions, I'd say it holds more water because it is bigger. Of course, that is always true :-) ...
*April 22, 2015*

**Math**

I think you are leaving something out. I assume they all have the same height. The area of a polygon increases with the number of sides, if the perimeter is constant. A square has more area than a triangle, and has the most area of any rectangle. A circle has the maximum area ...
*April 22, 2015*

**Math**

true only if 2P(A) = P(U)
*April 22, 2015*

**math**

clearly, it must be zero
*April 22, 2015*

**geometry**

no. it says that all squares are quadrilaterals That is, if a figure is a square, then it is a quadrilateral. after all, "quadrilateral" means four-sided...
*April 22, 2015*

**ipc**

if the rock is completely submerged, then its volume is 28.9-13.7 mL That's how much more stuff is in the cylinder after the rock is covered up.
*April 22, 2015*

**Math**

Good answer. By definition, √p is positive. In fact 1 is an extraneous solution.
*April 22, 2015*

**Math**

Not sure what you mean by saying that its elevation was 8850m "in 1998-2000" since it is always changing. From 1954 to "1998-2000" it rose 2 meters, or 200 cm. Not sure why the average lift rate is given, since we were given the final measurement. Question ...
*April 22, 2015*

**Analytic Geometry**

easy with vectors, but they are not usually a tool used in analytic geometry. slope of AB is -3/7 slope of CD is -3/7, so AB||CD slope of BC is 7/3 slope of AD is 7/3, so BC||AD since slopes are negative reciprocals, the pairs of sides are perpendicular So, ABCD is a rectangle.
*April 22, 2015*

**Analytic Geometry**

P = (x,2x) (x+3)^2 + (2x-1)^2 = (x-8)^2 + (2x+2)^2 ...
*April 22, 2015*

**algebra**

you know it is a factor if the remainder is zero.
*April 22, 2015*

**math**

this describes a line. what else do you need to know?
*April 22, 2015*

**math**

a + (a+24) = 164
*April 22, 2015*

**scale math**

since the scale is constant, (1/4)/1 = x/44
*April 22, 2015*

**Calculus**

-12 sinx/cos^2x = -12 secx tanx so, the integral is -12 secx + c -12 sec(0)+c = 4, so c=16
*April 22, 2015*

**integral calculus**

Try writing the fraction like this (3-x^7)/√(7+x^2) dx or something. I can't parse your text. I just know that √dx is meaningless, so your fraction is garbled. Use "/" for fractions, as formatting in the browser is problematic at best.
*April 22, 2015*

**math**

1/(2n) + 1/(2n+2) = 5/12
*April 22, 2015*

**Math**

.82/2.7 * 4.99
*April 22, 2015*

**Math**

#1 800*600*2250 ----------------- = 640,000 25*11.25*6 1s = 1/3600 hr = 0.0002777777... 4*162 = 648, so .04*.0162 = 648/(100*10000) = .000648 .2 = .04^0.5, so .2^3 = .008 = .04^1.5 1/.008 = 125 = .04^-1.5 11^2 = 121, so 10^3 = 1000
*April 22, 2015*

**Math**

visit: www.myassignmenthelp.net For any Kind of Assignment Help or Homework Help.
*April 22, 2015*

**math**

1395(1+.043*7) = ?
*April 22, 2015*

**math**

s^5+s^4+s^3+3s^2+2s = s(s+1)^2(s^2-s+2) I don't see any common factors with (s^2+3) so, what do you mean when you ask G(s) is: ?
*April 22, 2015*

**Algebra IMPORTANT**

Clearly, 10k+2 is 2(5k+1) so, 5k+1 = 2(2k) k = -1 The sequence is -2 -4 -8 ...
*April 21, 2015*

**please answer my question (math)**

You want n/12 = 3/4 since n/12 is the price of one flyboy, and a $3 spinner is the same as 4 flyboys (1/3 dozen)
*April 21, 2015*

**Calc**

h(t) = 625 + 20t - 16t^2 so, what is h(2)?
*April 21, 2015*

**Algebra**

so, did you graph it?
*April 21, 2015*

**accounting 100**

you're obviously embezzling!
*April 21, 2015*

**math**

345 = 3*5*23, so no perfect squares So, what methods of solution have you been given? The value will have to be an approximation, so use some numerical method or graphical method to get the value. interpolation, Newton's method, bisection, or something else.
*April 21, 2015*

**math**

a^3-b^3 - (a+b) (a-b)(a^2+ab+b^2) - (a+b) I suspect a typo. Had it been a^3-b^3 - a + b That would have been (a-b)(a^2+ab+b^2)-(a-b) (a-b)(a^2+ab+b^2-1) a^2-b^2+10a-2b+24 a^2+10a+25 - (b^2-2b+1) (a+5)^2 - (b-1)^2 (a+5+b-1)(a+5-b+1) (a+b+4)(a-b+6)
*April 21, 2015*

**functions**

slope: (600-100)/(2000-1960) = 12.5 Since 1960 is x=0, y = 12.5x
*April 21, 2015*

**Maths**

domain is clearly [0,200] m = 12n-120 so, the range is [-120,2280]
*April 21, 2015*

**maths, functions**

just solve D(p) = S(p) 1100-200p = 100p-100
*April 21, 2015*

**math**

2(8+13)=42
*April 21, 2015*

**math**

clearly d=6, since a6 = a4+12 = a4+2d so, since a4=a+3d=a+18=37, a=19 a1=a=19 a7=a+6d=19+6*6=44
*April 21, 2015*

**Chemistry**

.18/.27 = 2/3 Looks like Mg3O2, but that doesn't exist. So, what is happening?
*April 21, 2015*

**geometry**

1) in a 30-60-90 triangle, the sides are in the proportion 1:√3:2 2) h^2+10^2 = 20^2 3) a^2+4^2 = b^2 unless you know one of the other angles, there are lots of a and b which will work.
*April 20, 2015*

**Calc 1**

let u = 1/x then you have tan(3u)/u as u->0 we know that tan(u)/u -> 0, so tan(3u)/u -> 3
*April 20, 2015*

**calculus**

at height h, tanθ = h/50 sec^2θ dθ/dt = 1/50 so, plug in your numbers and evaluate dθ/dt
*April 20, 2015*

**Programing Logic and design**

days = ("Sunday",...,"Saturday") total=0 for i=1..7 display days[i] read amt[i] total += amt[i] end for for i=1..7 display days[i],amt[i] end for display "TOTAL:",total
*April 20, 2015*

**Math**

if the sides are x,y,z, then the package (surface area) is 2xy + 2xz + 2yz So, the new dimensions will be x=3, y+3, z+3 plug in your numbers to find the area
*April 20, 2015*

**math**

Hmmm. Your question is ill worded. I suspect you mean g(x) is the integral of e^(3t^2)-3t dt from 4 to x. Otherwise, we'd need the integral of e^(3t^2) which is not elementary. So, with that in mind, dg/dx = e^(3x^2)-3x
*April 20, 2015*

**derivatives**

Assuming you meant 5√ and not 5th root, y = (12x-18x^4+3)/(5√(6x^2-11x^4+2)) Using the quotient rule, y' = (12-72x^3)(5√(6x^2-11x^4+2)) - (12x-x^4+3)(5 / 2√(6x^2-11x^4+2))(12x-44x^3) ------------------------------------------- 25(6x^2-11x^4+2) You ...
*April 20, 2015*

**science 8th (:: 1 question**

you are correct.
*April 20, 2015*

**science 8th (::**

R=E/I You did E-I
*April 20, 2015*

**maths**

after t minutes, the temperature T will be T(t) = 300 - 15(t/2)
*April 20, 2015*

**maths**

each cycle advances the drunk 2 meters So, after 4 cycles and 4(5+3)=32 seconds, the drunk has advanced 8 meters. The next 5 steps take him to the end, so it takes 32+5 = 37 seconds.
*April 20, 2015*

**math**

T4 = 3T1 T7 = 2T3 + 1 Now just plug in the values for Tn and you have a+3d = 3a a+6d = 2(a+2d)+1 Now just solve for a and d.
*April 20, 2015*

**math**

if x is at 2%, then the rest (23500-x) is at 7%. So, add up the interest: .02x + .07(23500-x) = 795
*April 20, 2015*

**Math**

#1. Draw the number line -9 is to the left of -4, so -9 < -4 #2 C? Excuse me? You say that -2 = -4? Again, use the number line. #3 Nope again. You want C though I suspect that is an accident. The logic is: |2-5| = |-3| = 3 so, -|2-5| = -3 -3 = 8-11
*April 20, 2015*

**math**

You are correct on all three. A and B could be true with various numbers, but C is only true if p or q is zero.
*April 20, 2015*

**Trig**

as usual draw a diagram. If the height is x, then from distance x, x/h = cotθ so, h cot 48° - h cot 68° = 1
*April 20, 2015*

**Math**

60% = 3/5, so (3/5)(3/5)x = 36 x = 36(5/3)(5/3) = 100 for the boys, we have the average as 16*50.25 + 8*45.15 ----------------------- = 48.55 16+8
*April 20, 2015*

**Business Stats**

well, what value z corresponds to P(Z>z) = .84?
*April 20, 2015*

**chemistry**

depends on the temperature and pressure, no? But at STP, 1 mole fills 22.4 L, so ...
*April 20, 2015*

**Calc 1**

how about I do this one, and you at least try on the others? x^2+3x-18 = (x+6)(x-3) So, everywhere except at x=3, f(x) = x+6 That means we expect the limit to be 3+6=9 Using the suggestion, the limit is (2x+3)/1 = 2*6+3 = 9
*April 20, 2015*

**Math**

Hmmm. xy=50 2(x+y) = 34 The only factor pairs of 50 are 1,50 2,25 5,10 None of those add up to 17, so the sides will not be integers. To find them, you will need to solve a quadratic equation: x+y=17 x + 50/x = 17 x^2-17x+50 = 0 Now just use the quadratic formula.
*April 20, 2015*

**Math**

clearly it is not a square. 192 has several factors: 4x48 6x32 8x24 12x16 ... so, which of those factor pairs adds up to half of 64?
*April 20, 2015*

**Math**

D is indeed correct.
*April 20, 2015*

**Math**

nope. C is what you get if there's a flat fee of 2.19 and each gallon costs 1 more.
*April 20, 2015*

**algebra (urgent help needed)**

see the related questions below.
*April 20, 2015*

**Math**

looks good to me
*April 20, 2015*

**Calculus check and help**

so far, I don't see any of your work, just the answers others have provided. For B, if you have to split the area into two equal parts, and the integration goes from 0 to 1.136, that means that there is some z in that interval which bounds exactly half the area. So, you ...
*April 19, 2015*

**Calculus**

well, 1-sin^2 = cos^2, so you really just have sin/cos^2 = sec tan which I'm sure you recognize.
*April 19, 2015*

**Calculus**

the graphs intersect at (0,1) and (1.136,1.764) A The cross-sections have base of f(x)-g(x) and height 5. So, we add them all up: v = ∫[0,1.136] 5(1+sin(2x)-e^(x/2)) dx = 5(x - 1/2 cos(2x) - 2e^(x/2)) [0,1.136] = 2.1455 B The same thing, but the height is the same as the...
*April 19, 2015*

**Chem**

If the reaction is Pb(NO3)2 + 2NaCl = PbCl2 + 2NaNO3 then each mole of PbCl2 uses one mole of Pb(NO3)2. So, with 3.264/278.11 = 0.0117 moles of PbCl2 produced, the 2.00mL was .0117/.002 = 5.868M 5.868*80.7/100 = 4.735M original concentration
*April 19, 2015*

**Calculus**

If you mean f(x) = √(x-3) f is only defined for x >= 3 For that domain, it is clearly integrable. So, the interval is [3,∞)
*April 19, 2015*

**Calculus**

clearly the intervals have width 1. So, with right-hand endpoints, we need 1*(f(1)+f(2)+f(3)+f(4)) = 1+4+9+16 = 30 what was so hard about that?
*April 19, 2015*

**Science**

I'm not sure. There are various chemical reactions taking place all the time (plant and animal respiration, mineral formation, etc.) that consume or release water. So, not only is C probably true, but we don't know the long-term effects of the various processes taking ...
*April 19, 2015*

**statistics**

you want z such that P(Z>z) = .63/2 z = .896 So, the scores are ±0.896
*April 19, 2015*

**Math/Algebra**

By the end of 2012, that's 3 years, not 2. A: 4000*.0315*3 = 378.00 B: 4000(1.0315^3-1) = 390.03 Looks like C to me.
*April 19, 2015*

**Vectors**

unless the normals are parallel, the planes must intersect in a line.
*April 19, 2015*

**mass**

1.3 = .000081x x = 16049.38 So, subtract the 1.3g from that
*April 19, 2015*

**Math**

least perimeter will be a square. So, what are the sides of such a square?
*April 19, 2015*

**statistics**

P(Z>z) = 0.2 z = 70
*April 19, 2015*

**math**

If there are x lbs of peanuts, then there are (100-x) lbs of cashews. So work with the value of the mixture and its parts: 2.80x + 5.30(100-x) = 3.30(100)
*April 19, 2015*

**7TH MATH HELP**

#1. Nope: -12(3)-3 = -36-3 = -39 #2 ok #3 Nope: as x increases, y decreases #4 Nope: 8*2+5 = 16+5 = 21 #5 ok #6 Nope J(10, 5) -> (15,9) #7 Nope: you didn't change anything!
*April 19, 2015*

**math**

how are the cubes arranged? 1x6 or 2x3?
*April 19, 2015*

**math**

π r^2 h = 355 r^2 h = 113 the area a=2πrh+2πr^2 which we want to be small 113 is prime, so there will not be integer values. However, using integers to approximate, r h a/2π(r^2+rh) 3 13 48 4 7 44 5 4 45 6 3 54 Looks like r is near 4
*April 19, 2015*

**maths**

625^2+4 = 360629 = 157*2297
*April 18, 2015*

**Calculus**

as always, n ∑ 2/n f(5+2/n) k=1 Since you didn't specify the endpoints or the number of intervals, you can fill in the numbers.
*April 18, 2015*

**precalc**

just look up the information for x^2 = 4py Figure p, and you're halfway there.
*April 18, 2015*

**math**

you should recall that for y = ax^2+bx+c the vertex is at x = -b/2a So, figure that for x, then evaluate y there. Since this parabola opens downward, its vertex is the maximum value.
*April 18, 2015*

**AP Physics**

conserve momentum. The sum of the two momenta after the collision must be the same as the original momentum of the moving ball. No diagrams here, so there's no way to tell the direction of the first ball.
*April 18, 2015*

**Math**

clearly both those equations cannot be true, since 99≠57. The sum of T5 to T8 is S8 - S4 = 8/2(2a+7d) - 4/2(2a+3d) = 4a+22d = 114 Similarly, S15-S11 = 15/2(2a+14d) - 11/2(2a+10d) = 4a+50d = 198 Subtract those two to get 28d=84, or d=3 So, a=12 T21 = 12 + 20*3 = 72
*April 18, 2015*

**Math**

oops typo. I hit 2 instead of 3. I'm sure you noticed that, and can fix it.
*April 18, 2015*

**Math**

just get all the y stuff on one side of the equation. x = 2r + 3ty 3ty = x - 2r y = (x-2r) / 3t
*April 18, 2015*

**Math**

8x3 * 3 = 24x9 8x3 * 4 = 32x12
*April 18, 2015*

**maths**

If you're talking about exponents, 5x^-3 = 5/x^3 If not, please explain "index" to poor ignorant me.
*April 18, 2015*

**Physics**

it will be the same as if it were just dropped. So, how long does it take to drop 60m? technically, this is not quite true, since the aerodynamics of flight will probably keep it aloft longer than just dropping it.
*April 18, 2015*

**math**

d = (T12-T5)/(12-5) = (50-8)/7 = 6 T5 = a+4*6=8, so a = -16 Thus, the sequence is -16 -10 -4 2 8 ...
*April 18, 2015*

**Further maths**

f(x) = 2x-3 so, f(g) = 2g-3 since g = x^2+5, g(x-1) = (x-1)^2+5 so, f(g(x-1)) = 2((x-1)^2+5)-3 = 2x^2-4x+9
*April 18, 2015*

**trig**

You know that A(b) = 43+b so, if b=22, plug that in wherever there is a b: A(22) = 43+22
*April 18, 2015*

**Algebra**

(8a^3b^6)^(1/3) = 2ab^2 (16a^8b^-4)^(1/4) = 2a^2b^-1 2ab^2 / 2a^2b^-1 = a^-1b^3 = b^3/a
*April 18, 2015*

**calc**

marginal cost is dC/dx = 49(-3x+3lnx+28)/(28-3x)^2 so at x=7, dC/dx = (7 + 3 ln7)/49
*April 18, 2015*

**Physics**

since the volume is constant, 4^2 * 2 = .5^2 * v
*April 17, 2015*

**Math plane or spherical trig?**

which kind of trig are we using?
*April 17, 2015*

**geometry**

the length of AB is √45 = 3√5 the length of CD is √80 = 4√5 So, since dilations scale lengths linearly, CD/AB = 4/3 No idea what EF is supposed to be for...
*April 17, 2015*

**Math**

assuming you want integer ratios, the medium rectangle must be 3 times as large, or 24x9 Similarly, since 3 does not divide 32, and 8 does, the large one is 32x12
*April 17, 2015*