Tuesday

May 3, 2016
Total # Posts: 40,093

**Maths**

50 cot30° + 50 cot45°
*April 5, 2016*

**math**

surely it is 311*196=60956 or, as an estimate, 300*200 = 60,000 I guess their estimate is based on the average number of words per page. So, 60956 is close to 61,000.
*April 5, 2016*

**Math**

That is true. So, I guess your answer is ok, if you wanted it in ft^3. You neglected to mention that fact in stating the problem, or in giving units in your answer.
*April 5, 2016*

**Math**

how did 24 become 2?
*April 5, 2016*

**math**

It is in fact one of them. So, how do you use what I told you to get the whole population?
*April 5, 2016*

**math**

42/90 = 46.67% of the tagged squirrels. so, you can expect that 630 = 46.67% of the total population.
*April 5, 2016*

**Math**

looks good.
*April 5, 2016*

**Science**

Your answer makes no sense. The atom contains all three shells. Na is element #11. I think you omitted the question you are answering using the given data. (And I suspect it is shell 3)
*April 4, 2016*

**Algebra**

I'd say it's two positives & two negatives numbers on a number line in order of their absolute values from greatest to least
*April 4, 2016*

**Math Algebra 2**

something wrong with Reiny's previous solution? http://www.jiskha.com/display.cgi?id=1459772906
*April 4, 2016*

**Geometry**

google's first hit answers your question. Too bad you couldn't be bothered. https://www.algebra.com/algebra/homework/Bodies-in-space/Bodies-in-space.faq.question.975480.html
*April 4, 2016*

**Math**

any number.
*April 4, 2016*

**Math HELP!**

the law of cosines says that if x is the longest side and θ is the opposite angle, x^2 = 10^2 + 29^2 - 2*10*29 cosθ If x is less than 10^2+29^2, all three angles are acute. Of course, if x is not the longest side, then rearrange the numbers a bit to find other ...
*April 4, 2016*

**Math**

4/3 is greater than 1. So, how can 4/3 * 3.14 be less than 3.14?
*April 4, 2016*

**algebra**

you need to plug in the values and see whether they work on both lines. What do you get?
*April 4, 2016*

**math**

the line must have slope -5/6 So, using the point-slope form, that means the equation is y+5 = -5/6 (x+5) Now just rearrange that to the form you want.
*April 4, 2016*

**Math**

no. He did not live all full years. Figure the number of days in 2004 and 2008 that he lived, and then add 3*365 to that.
*April 4, 2016*

**math 4th grade no algebra**

if you are against using any algebra, just start trying numbers that add to 50. You want two which are 26 apart. 10+40=50, but they are 30 apart. Each number you add to 10 and subtract from 40 reduces the distance by 2. So, 12+38 = 50
*April 4, 2016*

**Math**

no idea. I can give you the answer, though. 3x5(5x6) = 3x5x30 = 15x30 = 450
*April 4, 2016*

**math 2**

t = ka/p So, pt/a = k is constant. So, you want a such that 6*1/a = 5*2/100
*April 4, 2016*

**Science**

looks better to me.
*April 4, 2016*

**Science**

Nope. The space station is in orbit. So, it can't be used to travel to and from.
*April 4, 2016*

**Calculus**

Without even knowing any calculus, it's easy to see that a linear approximation works best where the graph's curvature is less. Since a parabola is most curvy at its vertex, the best approximations are those farthest away. In this case, at x=4. So, since the tangent ...
*April 4, 2016*

**math( surface area )**

If the base has area B, then the prism's surface is 2B + 2*20(L+W) If L=W, then 2L^2 + 80L = 2400 L=W=20 See what you can do with L not equal W.
*April 4, 2016*

**Math**

since all the sides are magnified by a constant amount, the ratio of corresponding sides must be the same. So, 8/2 = x/4
*April 4, 2016*

**statistics**

1/6 * 1/6
*April 4, 2016*

**Math Algebra 2**

Aside from the typo where the c^2 gets lost, I'd just do it like this: m^2(1 - v^2/c^2) = m0^2 1 - (v/c)^2 = (m0/m)^2 (v/c)^2 = 1 - (m0/m)^2 v/c = √(1 - (m0/m)^2) To me, that makes it easier to see how the ratio of v to c is related to the ratio of the masses. ...
*April 4, 2016*

**simultaneous equation help**

From #1, y = (x^2-3)/(2x) so, in #2, 3x^2 - ((x^2-3)/(2x))^2 = 26 Or, assuming x≠0, (11x^4-98x^2-9)/(4x^2) = 0 (x-3)(x+3)(11x^2+1) = 0 x = -3 or 3 or complex values.
*April 4, 2016*

**Algebra**

If Diane takes x hours, 1/x + 1/(x-2) = 1/4
*April 4, 2016*

**math- geometry**

yes.
*April 4, 2016*

**Math (Rounding #s)**

It is 0.600 The 3rd decimal place is the thousandths. You need the two trailing zeros to specify the precision of the number.
*April 4, 2016*

**Math Algebra 2**

y = a(x-p)(x-q) using three different values of a will produce three different polynomials. Graphing them will produce parabolas that all cross the x-axis at the same two places (if at all), but are scaled differently.
*April 3, 2016*

**Trig**

recall that cos(a-b) = cosa cosb - sina sinb
*April 3, 2016*

**Math**

f = (2-3x)/(5-2x) f(a) = 3 when (2-3a)/(5-2a) = 3 2-3a = 15-6a 3a = 13 a = 13/3
*April 3, 2016*

**Math**

the pyramid has 1/3 the volume of the prism. Why wait for hours, when google can show you many discussions and formulas?
*April 3, 2016*

**maths help!**

know the density? mass = density * volume
*April 3, 2016*

**Math**

pyramid has 1/3 the volume of the prism.
*April 3, 2016*

**Maths**

tan^2(x/2) = (1-cosx)/(1+cosx)
*April 3, 2016*

**Maths**

sinx + sin3x = 4sinx cos^2x = 2sin2x cosx So, you have (2sin2x cosx - 2sin2x) --------------------------- (2sin2x cosx + 2sin2x) 2sin2x(cosx-1) --------------------- 2sin2x(cosx+1) = (cosx-1)/(cosx+1) Now take a look at the half-angle formula for tan(x/2)
*April 3, 2016*

**maths**

x^3-2x^2-13x-10 = (x+1)(x+2)(x-5) x^3-8^2 = (x+4)(x^2+4x+16) Looks like the LCM is just the product, since there are no common factors. Not sure what the minuscule has to do with it.
*April 3, 2016*

**Springville Middle School**

1/3 * pi * 15^2 * h = 7800
*April 3, 2016*

**Math**

h cot30 - h cot45 = 6
*April 3, 2016*

**Algebra**

{3,6,9,...}
*April 3, 2016*

**math**

clearly there were 3 times as many pears as oranges. So, 20 oranges.
*April 3, 2016*

**maths**

Is there a question somewhere in there?
*April 3, 2016*

**MATH**

if you are given only two of the dimensions, there is no way to determine the third. You need to know the volume, or the area, or a diagonal -- something to pin down that third dimension.
*April 3, 2016*

**cs203**

google is your friend. You might start here: http://stackoverflow.com/questions/14622371/how-do-i-print-a-binary-number-with-an-inputed-integer
*April 2, 2016*

**algebra**

or, since you have a point and a slope, you can just use the point-slope form: y-5 = 3(x-4)
*April 2, 2016*

**Math**

As long as the same dimension was used for rolling, the circumference is the same and the height is the same. So, the radii are the same, and both cylinders have volume π r^2 h.
*April 2, 2016*

**math**

okay. You know that all the s^(4x) and e^(-4x) stuff will zero out. So we need some quadratic stuff that will leave a particular solution. So, let's say that y_p is yp = Ax^2+Bx+C yp" = 2A yp" - 16yp = 2A - 16(Ax^2+Bx+C) So, we need -16Ax^2 - 16B + 2A-16C = 256x^...
*April 2, 2016*

**Mathematics**

(1-4)/(2-1) = -3/1 = -3 Clearly you need to plot the points and take a look at the line. + slopes are rising to the right - slopes are falling to the right
*April 2, 2016*

**Math**

clearly, 1275/1700 = ?
*April 2, 2016*

**Mathematics**

(1-3)/(-2-2) = -2/-4 = 1/2 Gotta watch those plus/minus values.
*April 2, 2016*

**math**

It's bad form to describe N(p) and then talk about x and y. Clearly, the N intercept is at -2818. What is p when N=0? Care to reconsider your answer?
*April 2, 2016*

**math**

Actually, it's the w-intercept in this case. At any rate, at the intercept, m(w)=0. That is, no money remains.
*April 2, 2016*

**algebra**

3/4 of 60 is 45 mi 45mi/9hr = 5 mi/hr what was she driving, a roller skate?
*April 2, 2016*

**Geometry**

h = 7√3, so each side is 14 A = (1/2)(14)(7√3) = 49√3 P = 3*14 = 42
*April 2, 2016*

**maths**

since (a+b)(a-b) = a^2-b^2 √3-√2 * (√3+√2)/(√3+√2) = (3-2)/(√3+√2) I assume by ig you mean log log(√3-√2) = -log(√3+√2)
*April 2, 2016*

**Calculus**

(x-3)^(2n)/4^n = (x-3)^(2n)/2^(2n) = ((x-3)/2)^(2n) So, as long as |(x-3)/2| < 1 it will converge.
*April 2, 2016*

**math**

Note that log_2(n) = 2*log_4(n) = 3*log_8(n) a = log_4(y) = (1/2) log_2(y) b = log_8(2y) = log_8(2) + log_8(y) = 1/3 + (1/3) log_2(y) b = 1/3 + (2/3) a 3b = 1+2a If logn = logm + 1, logn = logm + log10 = log(10m) so, n = 10m
*April 2, 2016*

**math**

20*8-20*5 = 20(8-5) = 60
*April 2, 2016*

**math**

8x + 5x = 260 find x, and then the amounts are 8x and 5x. Subtract to get your answer.
*April 2, 2016*

**Geometry**

Each leg is 10/√2, so P = 2*10/√2 + 10 = 10(1+√2) A = (1/2)(10/√2)(10/√2) = 100/4 = 25
*April 2, 2016*

**Math**

exactly.
*April 2, 2016*

**Math**

remember that distance = speed * time so, plug in your numbers.
*April 2, 2016*

**Math**

just multiply everything by 3!
*April 2, 2016*

**Math**

consider the sales tax. If it is 5%, the the final price is the retail price times 1.05, right? So, if our tax rate is r (expressed as a decimal), then the final cost of 70.75 is (1+r) times the sticker price. The tax amount is the final cost minus the sticker price: 70.75 - ...
*April 2, 2016*

**Math**

70.75(1-1/(1+r)) = 5.66 r = 0.0869 = 8.69%
*April 2, 2016*

**maths-help!!**

well, 240 = 4*60 so 2n can be any value from 0 to 58 so, n ...
*April 2, 2016*

**math**

(n*1.60)/(d*0.80) = (n/d)(1.60/.80) = (n/d)(2) so, the fraction is doubled. What percent increase is that? And it is not 200%!
*April 2, 2016*

**math**

(a*1.50)(b*0.80) = (ab)(1.20) so, the product increased by 20%
*April 2, 2016*

**math**

I can't quite picture your diagram, but 40 is 5/9 of the whole area. Maybe you can use that to get what you're after.
*April 2, 2016*

**math**

If each light consumes h watt-hours, then 4 lights running for n hours consume a total t of t = 4h*n Plug in your numbers. I can't figure out just what you're after.
*April 2, 2016*

**math - eh?**

Can you see how woefully incomplete your information is, if you want a solution?
*April 2, 2016*

**Math - incomplete**

why is x zero twice? Given your "table," I can fill in any numbers I want.
*April 2, 2016*

**maths**

S+H+J = 500 J = 3S S+33 = (5/6)(J-33) Oddly, I don't get integer solutions. Better check the problem and my setup.
*April 2, 2016*

**Computer science**

sure. That's why some computer folks are called systems analysts. Their basic software is called an operating system.
*April 2, 2016*

**Mathematics**

nope. (1-5)/(3-6) = -4/-3 = 4/3 better review the definition of slope.
*April 2, 2016*

**Mathematics**

did you plot the points? both have -3 for the x-coordinate, so the line is vertical. did you do the actual calculation? change in y divided by change in x? (-6 - -5)/(-3 - -3) = -1/0 is undefined.
*April 2, 2016*

**Math(PLZ HELP)**

#1 kg?? Really? That's over 2 lbs! Your paper clips must be a lot bigger than mine. #2 see #1 #3 ok #4 ok #5 ok #6 ok #7 a 15 ft border is added to each side, making both width and length 30 ft more. So, the new dimensions are 26+30 by 21+30 = 56 by 51
*April 1, 2016*

**Math**

Make a Venn diagram, and you can easily see that there are 70 students taking at least one of the classes, and thus 37 taking no class. Using the diagram, you can easily see how many students fit the questions; and thus the probabilities needed.
*April 1, 2016*

**Math (Real Analysis)**

epsilon-delta proofs use limits. abs(f) is continuous if f is continuous, because |f| = f if f>=0 |f| = -f is f<0 So, if the limit L exsists for f(x), it also exists for |f(x)|.
*April 1, 2016*

**math**

1 lb = 16 oz 3 lb = 48 oz You have given the number of lbs in 3 oz.
*April 1, 2016*

**trigonomentry**

no diagram, but I suspect that the Pythagorean Theorem can be used here.
*April 1, 2016*

**math**

no idea. There must be some other information here. If you know the height and the width, the length can be anything unless you also know the volume or area or a diagonal.
*April 1, 2016*

**math**

correct.
*April 1, 2016*

**math**

miles = 6 * minutes
*April 1, 2016*

**Dosage calculations**

1 tsp * 4.93 mL/tsp = 4.93 mL All that other stuff about number of days and number of doses is just noise.
*April 1, 2016*

**umd**

ok. Now what?
*April 1, 2016*

**Algebra 2**

font problems. Is that supposed to be sigma = 3.1? If so, just figure the mean, and find the maximum difference of each grade from the mean. Then divide that by 3.1 to get the number of std.
*April 1, 2016*

**math**

5.4ft/180m = 1.65m/180m = 1:109
*April 1, 2016*

**Math**

x changes by 1, y changes by -5 So, look for something like y = -5x Now adjust that so it fits.
*April 1, 2016*

**Math**

2340 + 100 - 50
*April 1, 2016*

**Math**

well, just plug in the x value and see whether you get the y value. For example, when x=0, 2*0 - 3 = -3 Nope, You want 3. Now try the others. One will work.
*April 1, 2016*

**Maths**

.40*30 = x(30+45) x = .16 or, since the volume has grown by a factor of 5/2, the concentration has been reduced by a factor of 2/5 to 16%
*April 1, 2016*

**trig**

Draw the triangle. sinθ = y/r cosθ = x/r tanθ = y/x In QII, y = 3 x = -4 r = 5 so, cosθ = -4/5 tanθ = -3/4
*April 1, 2016*

**Trig**

so, cos(x) = 1/7 and x is in QI or QIV so, x = 81.79 or 278.21 degrees no idea where you came up with your values for sin(x) and tan(x). ??
*April 1, 2016*

**Math**

you have to add x on each side, or 2x to both dimensions. So the perimeter is 2(5+2x+ 10+2x) = 30+8x
*April 1, 2016*

**math**

7:35
*April 1, 2016*

**Calculus**

draw your triangle You have the opposite leg=12 and the hypotenuse=13 So, the adjacent leg is √(169-144) = 5 cot(x) = 5/12
*April 1, 2016*