Sunday

November 29, 2015
Total # Posts: 35,841

**Math**

multiply the ratios by 16, and you get 48:16:48 Now add those up. It is not 1 apple to 3 cherry. It is 1 cherry to 3 apple.
*November 10, 2015*

**math**

You have to watch out for extra factors of 10, which add zeroes to the product. 40 x 50 ≠ 200
*November 10, 2015*

**College Physics**

A 10 kg mass (initially at rest) is attached to a rope, which is wrapped about a thin-walled hollow cyclinder of diameter D = 50 cm and mass = 20 kg. After the 10 kg mass drops a distance of 1.4 m, what is the angular speed of the cylinder? What is the acceleration of the ...
*November 10, 2015*

**algebra**

10s + 6c = 60
*November 10, 2015*

**Math**

how long does it take to go the 130 ft? 130/25 = 5.2 sec How long to go 15 ft? 0.6 sec So, at 5.2±0.6 the distance will be 15 ft Now what do you think?
*November 10, 2015*

**math**

-4y = 8x y = -2x now what do you think?
*November 10, 2015*

**Geometry**

(180-98)/2
*November 10, 2015*

**Algebra 2**

looks good to me. Though I'd be consistent and either completely factor the result, or expand it. #1 is some of each.
*November 10, 2015*

**Finite Math**

what is P(all red)? Subtract that from 1.
*November 10, 2015*

**math**

We need to know the relative walking/driving speeds. There are lots of solutions otherwise.
*November 10, 2015*

**Math**

looks good
*November 10, 2015*

**math**

80+60 = 140 miles
*November 10, 2015*

**Math**

Hmmm. 6*.60 = 3.60 So, I guess not. That's 12 cents too much. So, knock off 2 cents per can.
*November 10, 2015*

**Pre-Calculus**

using the law of cosines, we know that 7^2+15^2-2*7*15 cosθ = 10^2 cosθ = (7^2+15^2-10^2)/(2*7*15) = 29/35 So, that means the other diagonal, x is x^2 = 7^2+15^2+2*7*15*29/35 = 448 x = 8√7
*November 10, 2015*

**ipc**

PV=kT is constant. That means V/T = k/P is constant. So, you want V such that 30/(273+10) = V/(273+293)
*November 10, 2015*

**maths**

google is your friend. Just search for fractions.
*November 10, 2015*

**need tips**

I suggest that you not help them with their grammar or spelling...
*November 10, 2015*

**geometry**

No diagram.
*November 10, 2015*

**math, physics**

If x is the speed, then since distance = speed*time, 6(x-1.5) = 5(x+1.5)
*November 10, 2015*

**geometery**

recall that the area a = 1/2 r^2 θ Now just convert 68° to radians and plug in your numbers.
*November 10, 2015*

**College Algebra**

x/2 + 150 = 2988
*November 10, 2015*

**Math**

(.32 - 2*.03)/.02
*November 10, 2015*

**Trigonometry**

Since the radii are in the ratio of 5/8, and they both move the same amount of belt, their speed is in the ratio 8/5. So, what is 80 * 8/5 ?
*November 10, 2015*

**trigonometry**

50cos40° assuming 40° is a compass heading. If the angle is measured in the customary way from the x-axis, then you'd have 50sin40°
*November 10, 2015*

**trigonometry**

7cos36°
*November 10, 2015*

**math**

(-54-42)° / (-12°/hr) = -84/-12 = 7 hr
*November 10, 2015*

**pre algebra**

how about 27/31
*November 10, 2015*

**maths**

Not sure what to do with that comma: 4^(x+2)-16, 2^(x+1)+1=0 clearly 2^(x+1)+1=0 has no solutions, since 2^(x+1) is always positive. Maybe you can clarify just what it is you have, and what it is you want...
*November 10, 2015*

**PreCalc/Calc**

review the definition of cotθ. Draw a diagram, and it is clear that the width w is given by w = 10000(cot44°-cot58°)
*November 10, 2015*

**Calc**

since cos(t) starts at the top, and we are starting at the bottom (I assume, though it is not explicitly indicated), h(t) = -cos(kt) the wheel's radius is 7, and the center is 8m up, so h(t) = 8-7cos(kt) The period is 1/3, so 2π/k = 1/3, and k=6π h(t) = 8-7cos(6...
*November 10, 2015*

**Algebra**

w*3w = 108 so, w=6 p = 2(w+3w) = ?
*November 9, 2015*

**math**

xy = 3.6 x+y = 3.8 x + 3.6/x = 3.8 x^2 - 3.8x + 3.6 = 0 (x-2)(x-1.8) = 0
*November 9, 2015*

**math**

start off with the point-slope form. The slope is 5, so y-15 = 5(x-2) Now just rearrange the equation into slope-intercept form.
*November 9, 2015*

**math**

well, just list the digits. You have the place values... 325.312
*November 9, 2015*

**math**

The number of girls in the choir is 4 times the number of boys in the choir. The total number of students in the choir is 60. How many girls are in the choir?
*November 9, 2015*

**Math**

y=9x-5 y=x+11
*November 9, 2015*

**12th**

no idea. How many std away from the mean is considered unusual?
*November 9, 2015*

**precalcus**

P e^(.075*9) = 60000
*November 9, 2015*

**Calculus**

u = x^2 du = 2x dx Now you have 5/2 ∫ u^2 e^u du Now use integration by parts twice.
*November 9, 2015*

**Math**

any odd number cannot be divided into two equal parts.
*November 9, 2015*

**Math**

you have to find the density of vinegar, since weight = density * volume So, look up the density of vinegar in lbs/gal. You will probably find it as g/mL, which you will have to convert into lb/gal. There are unit conversion sites online. One such site, http://www....
*November 9, 2015*

**math**

If you meant that the temperature drops by 5° every 3 hours, you are correct. However, the problem said that the temperature dropped by 5° in each of the 3 hours. In that case, the temperature at 3:00 would be 8 - 3*5 = -7°
*November 9, 2015*

**Algebra 1**

8(x+11) = 123
*November 9, 2015*

**Calculus**

dP/dt = 9√t P(t) = 6t^(3/2)+c P(0) = 700, so c=700 and thus P(t) = 6t^(3/2)+700 as you can see, this function models some slow growth. You sure dP/dt is not proportional to P?
*November 9, 2015*

**Algebra**

huh? You cannot look at the numbers 35 30 25 20 and tell that they are decreasing? You evidently can, since your choice is correct. Also, since the changes in Players are evenly spaced, and so are the changes in Minutes, the function is linear.
*November 9, 2015*

**math models**

y = k/x now just plug in your values: 2 = k/8 k=16
*November 9, 2015*

**math**

x(1+.10*t)=400 x(1+.04*t)=200 Now just solve for t
*November 9, 2015*

**physics**

s = 34.4t - 1/2 at^2 = 61.8 v = 34.4 - at = 0 solving for a, a = 9.57 m/s^2 So, now you know that F=ma
*November 9, 2015*

**Geometry**

R, S, and T are the vertices of one triangle. E, F, and D are the vertices of another triangle. m<R = 60°, m<S = 80°, m<F = 60°, m<D = 40°,? RS = 4, and EF = 4. Are the two angles congruent? If yes, explain how and identify which segment is ...
*November 9, 2015*

**algebra**

PV=kT is constant, so you want V such that .953V = .984*22.5
*November 9, 2015*

**math, a.p. calc**

On the other hand, if you meant g'(x) = (x^2–16)/(x−2) = x+2 - 12/(x-2) then g(x) = x^2/2 + 2x - 12log(x-2) + c g(3) = 9/2 + 6 - 12log(1) + c = 4, so c=-13/2 g'(3) = -7 and the tangent line is y-4 = -7(x-3) and the graph is at http://www.wolframalpha.com/...
*November 9, 2015*

**calculus**

∫[-π,π]∫[-π,π] 1+x^2 siny + y^2 sinx dy dx = ∫[-π,π] 2π dx ...
*November 9, 2015*

**maths**

I have no idea what that means. Try using log_9(x) to mean log (base 9) of x If I try to parse your notation, I'd say 9 log_3(12) = 9 (log_3(3)+log_3(4)) = 9(1+2log_3(2)) = 9 + 18log_3(2) But somehow I doubt that is what you had in mind.
*November 9, 2015*

**Calculus**

cos(a+b) = cosa cosb - sina sinb cos(a-b) = cosa cosb + sina sinb since (x-y)(x+y) = x^2-y^2, that gives us (cosa cosb)^2 - (sina sinb)^2 = cos^2a cos^2b - sin^2a sin^2b = cos^2a (1-sin^2b) - (1-cos^2a) sin^2b = cos^2a - sin^2b = cos^2a - (1-cos^2b) = cos^a + cos^2b - 1 I ...
*November 9, 2015*

**VCU**

2L = 2000 cm^3, so that gives 1g/cm^3 * 2000cm^3 = 2000g
*November 9, 2015*

**VCU**

clearly, that would be 25.0/29.4 g/cm^3
*November 9, 2015*

**trig**

draw a diagram recall the definition of cotθ then you can see that the height h is found using h cot22.9° - h cot38.7° = 27
*November 9, 2015*

**Calculus**

using washers, v = ∫[0,9] π(R^2-r^2) dy where R=2+√(9-y) and r=2 v = ∫[0,9] π((2+√(9-y))^2-4) dy v = 225π/2 or, using shells v = ∫[0,3] 2πrh dx where r = x+2 and h = 9-x^2 v = ∫[0,3] 2π(x+2)(9-x^2) dx = 225π/2
*November 8, 2015*

**Algebra**

make sure that the amounts of glycol in each part add up to the total. If there are x gal of 40%, then the rest (100-x) is 60%, so we have .40x + .60(100-x) = .48(100)
*November 8, 2015*

**Math**

just plug and chug: f(x+h) = 2(x+h)^2+4(x+h) = 2x^2+4xh+2h^2+4x+4h now subtract f(x) = 2x^2+4x and you have 4xh+4h+2h^2 Now divide all that by h, and you have 4x+4+2h lim as h->0 = 4x+4
*November 8, 2015*

**math**

the area of the garden is 96 ft^2 So, you want the walk of width w to also have 96 ft^2 of area. That means that (12+2w)(8+2w) = 96+96 Now just solve for w.
*November 8, 2015*

**Math**

well, just solve 160x/(100-x) = 240 160x = 24000 - 240x 400x = 24000 x = 60
*November 8, 2015*

**Math**

(x-120) * (1 - 2/3) = 1/5 x x = 300 check: 300-120 = 180 2/3 of 180 = 120, leaving 60 50 is 1/5 of 300
*November 8, 2015*

**math**

better study your materials for partitive division story Till you understand that, there's not much hope. I'm sure that there will be examples with the explanation. Or, remember that google is your friend. I used it, and this is my first hit: http://www.math.niu.edu/...
*November 8, 2015*

**Algebra 2**

you are correct. All polynomials are defined over the entire set of real numbers.
*November 8, 2015*

**Math**

number: n 3 less than n: n-3 half of that: (n-3)/2
*November 8, 2015*

**math**

no way to tell. However, the probability that they answered "yes" to the question is 325/(325+294) = 0.525 Assuming the 619 people were chosen at random. Poorly worded problem.
*November 8, 2015*

**Mthombo**

area goes up as the square of the scale. So, the new perimeter: 30 * 1/5 area: 50 * (1/5)^2
*November 8, 2015*

**8th grade pre algebra line segments**

geometric argument for what? You can use a grid and the Pythagorean Theorem to determine lengths of line segments.
*November 8, 2015*

**please give me a site or answer!!!!**

Hard to believe you'd go asking for help without even trying google first. First hit: the one above.
*November 8, 2015*

**technical college**

first, construct your triangle. Then, follow the instructions found here: http://www.mathopenref.com/constincircle.html since the incenter is the intersection of the angle bisectors.
*November 8, 2015*

**math**

recall that C = 2πr
*November 8, 2015*

**Math - Arithmetic question**

yes. since the terms have a constant difference, that just keeps getting added over and over. The sum will always diverge (unless d=0).
*November 8, 2015*

**college**

C works for me.
*November 8, 2015*

**math**

A(.075*15/12) - A(.125*8/12) = 32.50 x = 3120
*November 8, 2015*

**Geometry**

those are strange polar coordinates, but what the heck. In rectangular form, they are (-5.940,0.847) and (1.980,0.282) The midpoint of that segment is (-1.980,0.564) The slope of the segment is -0.071 So, since the diagonals are perpendicular, the other diagonal has slope 14....
*November 8, 2015*

**math**

nope. diagonals of a parallelogram bisect each other.
*November 8, 2015*

**match**

there are 6 red balls. If P(red) = 1/6, that means there are 36 balls in all. So, how many more do you need?
*November 8, 2015*

**calculus**

That's a lot of places to make mistakes. I get 2y dx/dt + 2x dy/dt - 4/3y^3 dx/dt + 4x/y^4 dy/dt 2y(1 - 2/3y^4) dx/dt + 2x(1+2/y^4) dy/dt = 0 -4(23/24)(-6) + 6(9/8) dy/dt = 0 dy/dt = 27/92 Maybe you can work out whether we are both wrong! Actually, I plugged in the line 2...
*November 8, 2015*

**calculus**

Just use the product rule and chain rule: 2xy - 4x/3y^3 = 48 2y dx/dt + 2x dy/dt - 4/3y^3 dx/dt + 4x/y^4 dy/dt = 0 Now just plug in the numbers and solve for dy/dt
*November 8, 2015*

**Calculus**

the spherical cap is discussed below. Having the answer to part (4) make sthe other parts easy. http://mathworld.wolfram.com/SphericalCap.html
*November 7, 2015*

**History**

Thank you -- it's an interesting concept
*November 7, 2015*

**History**

Does urbanization cause cities to have a growing influence on society
*November 7, 2015*

**Calculus**

Recall that the volume of a spherical cap of radius R and height h is 1/3 πh^2 (3R-h) Now you can use that and the density to find the mass of the fluid. Add that to the empty container.
*November 7, 2015*

**Calculus - my bad**

yeah, i misread f(x)
*November 7, 2015*

**Calculus**

all those words! f(x) = |x + π/2| g(x) = |cos x| Not sure what you mean in part (a). f(x) and g(x) intersect in a single point: (-π/2,0) See the graphs at http://www.wolframalpha.com/input/?i=plot+y%3D|x%2B%CF%80%2F2|%2C+y%3D|cos+x| Maybe I misread your text.
*November 7, 2015*

**Algebra II**

The word "factor" should tell you that multiplication is involved. Hence, y = (1/2)(x)
*November 7, 2015*

**Calculus**

cot^3 = cot cot^2 = cot (csc^2 - 1) = cot csc^2 - cot = cot csc^2 - cos/sin Now your way should be clear, since d/dx(cot) = -csc^2 d/dx(log sin) = cos/sin
*November 7, 2015*

**Maths**

recall that this is just 2 cosh(x). d/dx (cosh x) = sinh(x) sinh(x) = 0 at x=0 so, the minimum value is 1+1 = 2 (or 2cosh(0) = 2) Or, if you insist on the hard way, y' = 2e^2x - 2e^-2x = 2e^-2x (e^4x - 1) y'=0 at e^4x=1, or x=0.
*November 7, 2015*

**Algebra**

what, you cannot add up 5,7,9,11 ?
*November 7, 2015*

**Futa**

125+180 = 305
*November 7, 2015*

**math**

dy/dt = 3x^2+3 dx/dt so, since Vx=dx/dt=2, dy/dt = 6(x^2+1) at x=1, Vy=dy/dt = 12 so, V=√(4+144) tanθ = Vy/Vx = 6
*November 7, 2015*

**maths**

since time=distance/speed, 100/8 - 100/10
*November 7, 2015*

**maths**

the inside volume is 48*48*36 The outside volume is 49*49*36 subtract to find the wood.
*November 7, 2015*

**Calculus**

we have x^2+y^2 = 15^2 x dx/dt + y dy/dt = 0 Let x be decreasing, and y increasing. Then when y=9, x=12, and we have 12 dx/dt + 9*4 = 0 dx/dt = -3
*November 7, 2015*

**Calculus**

so, I guess the real(!) answer is indeed that there is no absolute max value.
*November 7, 2015*

**Calculus**

on the given domain, f(x) = x^2-4x+7 minimum is f(2)=3 limit as x->0 of f(x) = 7 f(3) = 4 So, abs min = -9 abs max = 7 not strictly true, since f(0) is undefined, and there is no maximum number less than 7. See the graph at
*November 7, 2015*

**math**

10000/8300 = 1.205 So, n(t) = 8300 * 1.205^n
*November 6, 2015*

**Help Please, Oh Please--Algebra**

terms are separated by + or - signs. So, there are 3 terms, making this a trinomial.
*November 6, 2015*