Friday

September 30, 2016
Total # Posts: 44,265

**math**

each ate 3/8 so, 5/8 remained

*August 29, 2016*

**math**

Many choices: 3/5 4/6 5/7 ... didn't you even try at all?

*August 29, 2016*

**science**

Its name?

*August 28, 2016*

**Math**

If Matt takes m hours, then Carla takes 4m. So, together, 1/m + 1/4m = 1/8 5/4m = 1/8 m = 10

*August 28, 2016*

**Math science**

end of what? zero is just a number, like any other. Though it does have several unique properties. There is no "end" number.

*August 28, 2016*

**Urgent Math**

I like it! But the half-angle formula would have gone directly to (cos2x - 1)/sin2x = -tanx Then we'd have ∫tan^2(x) dx = ∫sec^2(x)-1 dx = tanx - x + C

*August 28, 2016*

**Urgent Math**

∫(cot2x-csc2x)^2 dx ∫ cot^2(2x) - 2cot(2x)csc(2x) + csc^2(2x) dx ∫ 2csc^2(2x) - 1 - 2cos(2x)/sin^2(2x) dx Now everything is standard forms, so you get -cot(2x) - x + 1/sin(2x) csc(2x) - cot(2x) - x or, you can go on to get (1-cos(2x))/sin(2x) - x (1 - 2cos^2(...

*August 28, 2016*

**physics**

the height is modeled by the function h(t) = 60 + 30t - 4.9t^2 max height is at the vertex of the parabola, at t = -b/2a = 30/9.8 Use that to evaluate h(t) there. It hits the ground when the height has dropped to zero. So, just solve 60 + 30t - 4.9t^2 = 0

*August 28, 2016*

**physics**

while I did miss on the velocity/speed problem, I think we can assume that if he is driving east, as given, that is the direction of the straight road... But, it's fun to be picky when the problem is poorly stated.

*August 28, 2016*

**physics**

assuming (1) that you meant 48.0 km/hr (2) that speed was achieved during the 144km trip then since time = distance/speed, it would take 144/48 = 3 hours

*August 28, 2016*

**Math**

Just substitute in a desired value. f(x) = 3x+2 f(a) = 3a+2 f(2a) = 3(2a)+2 = 6a+2 f(4) = 3(4)+2 = 14 and so on

*August 28, 2016*

**Math**

A = x(3-2x) = 3x-2x^2 P is ok your conclusion is correct, except that 3-2x = -1 when x is 2.

*August 28, 2016*

**Math**

solve what? The only thing we can say is that the bearing of q from p is 180+55 = 235°

*August 28, 2016*

**math**

aside from noting that (x^3+y)^0 = 1 this is a simple exercise in expanding powers of binomials. Type in your expression at wolframalpha.com to verify your results. >wink wink< Be sure to use ^ for powers, or it will just multiply.

*August 28, 2016*

**College math**

just plug it into your formula: 10000(1 + .09/12)^(12*7)

*August 28, 2016*

**Trig**

Think of a 5-12-13 triangle. Draw the triangle and review your basic trig functions.

*August 28, 2016*

**Chemistry**

1 mole contains Avogadro's Number of K+ ions

*August 28, 2016*

**calcus**

Draw the base line AB of the triangle. Now construct the perpendicular bisector of AB. The vertex C can be anywhere up along that bisector to form an isosceles triangle.

*August 28, 2016*

**calcus**

Come on - just because you are making the triangle less tall does not mean that the base has to change. It is still isosceles. The only sticking point comes when the two legs shrink down to 1/2 the base length. At that point the triangle has flattened into a straight line.

*August 28, 2016*

**calcus**

If the leg length is s, the height of the triangle is h^2 + (10√3)^2 = s^2 or h^2 + 300 = s^2 The area is a = 1/2 bh = 10h√3 = 10√3 √(s^2-300) when the triangle is equilateral, s=20√3 da/dt = 10√3 s/√(s^2-300) ds/dt = 10√3 * 20&#...

*August 28, 2016*

**geometry**

just set the two expressions equal to each other: 4(x+2) = 2(3x+2) + 2(x-1) Now you can solve for x and then evaluate either expression for the perimeter.

*August 28, 2016*

**Bio physics chemistry pre medical**

the molar mass is 20*C+30*H+O where C,H,O are the atomic masses of the atoms. Now divide 500g/molarmass * Avogadro's Number review what moles are

*August 28, 2016*

**Math**

2(6+2) just the perimeter, in meters. Kind of boring, using 1m as the edge width.

*August 28, 2016*

**Math**

(30-2w)(20-2w) = 375

*August 28, 2016*

**Math**

v = π/4 d^2 h now use your numbers

*August 28, 2016*

**Math or Maths???**

prolly from mathematics -- "maths" retains the "s"

*August 28, 2016*

**maths**

Oops. I worked an A.P., not G.P. a = ar + 4 ar + ar^2 = "2 by 2/3" Now just solve for a and r and then list the first 4 terms.

*August 28, 2016*

**maths**

a = (a+d)+4 (a+d)+(a+2d) = "2 by 2/3" (whatever that means) Anyway, now just solve for a and d, and then list the first 4 terms.

*August 28, 2016*

**Math Need Help**

Just do a long division first: ((2x+4)(2x-1))/(3x-2) = 4x/3 + 26/9 + 16/9 * 1/(3x-2) so, ∫((2x+4)(2x-1))/(3x-2) dx = 2x^2/3 + 26/9 x + 16/27 log(3x-2) + C

*August 28, 2016*

**Maths**

If the 3rd side is x, then we must have 8-6 < x < 8+6

*August 28, 2016*

**math**

google is your friend. See http://www.mathopenref.com/coordtrianglearea.html

*August 28, 2016*

**percentage**

20% of (12000-2000) = 2000 30% of the remaining 10000 is 3000 so now you can see how much she saves monthly, and thus can figure the annual savings.

*August 28, 2016*

**Calculus**

Your typo does not help, but the problem is discussed here: http://math.stackexchange.com/questions/217026/show-that-f-has-at-most-one-fixed-point remember that google is your friend.

*August 28, 2016*

**Math College 115**

(7.5-6.5)/(2009-2004)

*August 28, 2016*

**math**

when you said quadrilateral, that means four sides.

*August 28, 2016*

**maths**

The two angles form a straight line, so how many degrees is that in total?

*August 28, 2016*

**Math**

well, let XY=2 and YZ=5 XY/XZ = 2/7

*August 27, 2016*

**College Math**

(4*50)/350 = 4/7 = 57%

*August 27, 2016*

**Math**

use either point in your equation: -3/13(-10)+b = 3 30 + 13b = 39 13b = 9 -3/13(-2)+b = -5 6+13b = -65 13b = -71 Hmmm. They should come out the same. Let's check your slope: m = (-5-3)/(-2+10) = -1 So, y = x+b -(-10)+b = 3 10+b = 3 b = -7 -(-2)+b = -5 2+b = -5 b = -7 So, ...

*August 27, 2016*

**Algebra 1**

how vewwy vewwy wude!

*August 27, 2016*

**Math**

differences: -1/3, 1, -3 ratios: 0, ∞, -2 since neither is constant, it is neither an A.P. or a G.P. So, how to figure the next terms? Note that the differences form a G.P., with the next terms 9,-27,81 Adding those to -2, we get 7,-20,61, or choice (A)

*August 27, 2016*

**Maths**

If you take the time to list the possible events qnd the contents of the jqr qfter eqch, the qnswer will become cleqr. qnnoying, isn't it?

*August 27, 2016*

**Maths**

2/3 * 2/3

*August 27, 2016*

**real analysis**

google is your friend http://math.stackexchange.com/questions/283987/interior-closure-and-boundary-of-the-sets-of-all-rational-and-irrational-number

*August 27, 2016*

**Higher Math**

tan10x = 2tan5x/(1-tan^2(5x)) so, 2tan(5x)/(1-tan^2(5x)) = 1/tan(5x) 2tan^2(5x) = 1-tan^2(5x) 3tan^2(5x) = 1 tan 5x = ±1/√3 Now use that to get your reference angles and produce as many solutions as your domain requires.

*August 27, 2016*

**Math**

height: h width: h+4 length: w+8 = h+12 h(h+4)(h+12) = 512 all the factors of 512 are powers of 2, so we have 2^9 = 512 2+3+4 = 9 2^2 * 2^3 * 2^4 = 512 4*8*16 = 512

*August 27, 2016*

**math**

when n=1, A1 = -7*1+8 = -7+8 = 1 now just start subtracting 7 again and again.

*August 27, 2016*

**math**

since you keep multiplying by -1, there will be (n-1) of them by the nth term.

*August 27, 2016*

**math**

Check the ratio between terms. If it constant, choose it. For example, -6/2 = ?

*August 27, 2016*

**math**

F is the first term None of the choices identifies the first four terms

*August 27, 2016*

**maths**

9999999 - x = 6543210

*August 27, 2016*

**Math**

heads: s+a=10 legs: 8s+6a=68 Now just solve for s and a.

*August 27, 2016*

**math just for fun**

111*16 = 1776 pages Looks like 4 reams will do the job. So, how much will that cost? If only paying for the paper used, that would end up as 1776/500 * 3.88

*August 27, 2016*

**math**

.70p = 35

*August 27, 2016*

**Math**

Also, note that you have not said which numeric grade is equivalent to a B. Nor have you said how many items remain to be graded. If you can't specify the requirements, how can you expect a solution?

*August 26, 2016*

**Math**

512 = 8^3 = 2^9

*August 26, 2016*

**math**

it has an inverse, since f^-1(x) = ∛(x-8) + 2 Also, you know that g(x) = x^3 is 1-to-1, and f(x) is just g(x) shifted by (2,8). More formally f(x) is one-to-one if f(a) = f(b) means that a = b so, let's say that f(a) = f(b) That means that f(a) = f(b) (a-2)^3+8 = (b-...

*August 26, 2016*

**Physics**

you forgot the depth: 1cm Though it makes the units come out, it does not affect the final numerical value. Looks good.

*August 26, 2016*

**12th grade physics**

1000 cosθ where sinθ = 15/40

*August 26, 2016*

**algebra**

what do you mean by reasonable? Is 23.62 less reasonable than 23 ?

*August 26, 2016*

**maths**

minimum cost is at the vertex of the parabola. As usual, that occurs at x = -b/2a = 10/0.5

*August 26, 2016*

**geometry**

clearly AB has been rotated 1/4 turn to the left. Since the triangle is still the same size (AB has the same length as A'B'), we just need to find the translation. (-3,4) --> (-2,-3) so it has been moved by (1,-7) Now just convert those two changes to your standard ...

*August 26, 2016*

**geometry**

With no figures to consult, it's very hard to say ...

*August 26, 2016*

**Math**

seven digit number xxxxxxx digit 3 in my ten thousands and tens places xx3xx3x carry on from here

*August 26, 2016*

**calculus**

see whether you can come up with the answer shown at http://www.wolframalpha.com/input/?i=inverse+%7B%7B16,1%7D,%7B1,16%7D%7D

*August 26, 2016*

**calculus**

Review the definition of matrix multiplication. See if you can come up with the answer shown at http://www.wolframalpha.com/input/?i=%7B%7B3,8%7D,%7B6,3%7D%7D*%7B%7B4,5%7D,%7B4,4%7D%7D

*August 26, 2016*

**algbra**

I believe √100 = 10, not 5 anything that is only concerned with integers and fractions is rational. √19 is irrational nope pi is irrational the √ values are irrational only (a) is rational I think you have some reviewing to do...

*August 26, 2016*

**calculus**

eh? just subtract corresponding elements: [1 5 2] ...

*August 26, 2016*

**Math**

1.08x <= 18

*August 26, 2016*

**algebra 1**

both correct. Although, I don't think Best Buy sells cereal...

*August 26, 2016*

**Maths**

As always, draw a diagram and review your basic trig functions. If B is at height h above A, then h/600 = sin11° Now, if the distance CA is x, x = 600cos11° + h cot23°

*August 26, 2016*

**maths**

since 3/4 of each, that means 3/4 of their total. (3/4)t + (3/4)c = (3/4)(t+c)

*August 26, 2016*

**Math**

recall that for odd powers, a^n + b^n = (a+b)(a^(n-1) - a^(n-2)*b + ...) since 4+6=10, the product is a multiple of 10, so dividing by 5 leaves a remainder of zero. (D)

*August 26, 2016*

**physics**

solve 35t - 4.9t^2 = 0

*August 26, 2016*

**Lost**

3000c - 900 = 3750 3000c = 4650 c = 4650/3000 or, more directly c = (p+e)/n

*August 26, 2016*

**Math**

if n is any value except zero, n/n = 1

*August 26, 2016*

**Math**

list the pairs of factors of 60 and 75 The more factors, the more ways they can be arranged.

*August 26, 2016*

**Analogy**

eighteen:even::thirty-three:odd

*August 26, 2016*

**Chemistry**

convert to moles, then multiply by Avogadro's Number

*August 25, 2016*

**Math**

see related questions below

*August 25, 2016*

**Physics I - Modern**

it's mv/√(1 - v^2/c^2) see http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/relmom.html

*August 25, 2016*

**Math**

well, a 150lb person on the moon would weigh (150/120) * 20 = 25lb

*August 25, 2016*

**Math**

no idea. try google

*August 25, 2016*

**physics**

40 mi/hr * 1609m/mi * 1hr/3600s * 60s/min * 3min = 1073.7 m

*August 25, 2016*

**7th grade math**

clearly, two of the three possible discounts will give enough discount so that the final price with tax will be less than $25. So, probability is 2/3

*August 25, 2016*

**7th grade math**

There are 8 possible outfits with the shoes and bottoms. So, what is the smallest multiple of 8 that is at least 35? Using n tops, he gets 8n outfits.

*August 25, 2016*

**Pre-calculus**

Since the axis is horizontal, the general equation is x = a(y-k)^2 + h Since the vertex is at y=k, k = h and that means x = a(y-k)^2 + k Using the two points, we have a(-2-k)^2 + k = 6 a(4-k)^2 + k = 3 solve those, and you wind up with x = 1/4 (y-2)^2 + 2 x = 5/36 (y-14/5) + ...

*August 25, 2016*

**math**

1/4 + 5/8 + x + 3/4 = 2 1/2 Now just solve for x did you get 7/8 ?

*August 25, 2016*

**Math**

since distance = speed * time, if your speed is x, then 2*x + 2*2x = 258

*August 25, 2016*

**physics**

The ball's height is modeled by h(t) = 15t - 4.9t^2 The ball will be 8m high twice: on the way up and on the way down. These times can be found by solving 15t - 4.9t^2 = 8 See http://www.wolframalpha.com/input/?i=15t+-+4.9t%5E2+%3D+8 If you include the units in your ...

*August 25, 2016*

**MATH**

(36-30)/30 * 100

*August 25, 2016*

**Maths**

there are 48*16 food portions after 4 days, 48*4 portions have been eaten. So, there is enough for (48*16 - 48*4)/(48-12) = 16 days or, after 4 days, 1/4 of the food is eaten. That leaves enough for 12 days for the full population. But, the population is now 3/4 what it was, ...

*August 25, 2016*

**value**

m/d = 8/5 d = 15, so m=24 so, what is m-6?

*August 25, 2016*

**Maths**

start with cot(x/2) = sinx/(1+cosx) and see where you can take that.

*August 25, 2016*

**maths**

just list the factors of 72, and work with that, depending on how many piles you want: 1 72 2 36 2 2 18 2 2 2 9 ... 3 3 8 3 24 and so on

*August 25, 2016*

**alg. Connections**

total points for an 85 average: 85*3 = 255 Points so far: 81+86 = 167 So, haw many does she still need?

*August 25, 2016*

**algebra HELP MRS SUE**

B is better :-)

*August 25, 2016*

**lauren**

If $x at 11%, then the rest $(6300-x) is at 7%. So, just add up the interest: .11x + .07(6300-x) = 565

*August 25, 2016*