Sunday

October 23, 2016
Total # Posts: 45,179

**Set Theory**

34-22

*October 8, 2016*

**Math**

no. see the "thousandths"? There will be a decimal point. one thousandth is 1/1000 or .001

*October 8, 2016*

**Loan**

Just make the usual Venn diagram. The number is 60+23-68 = 15

*October 8, 2016*

**physics**

1/5.4^2 * g

*October 8, 2016*

**College Algebra**

1/x = 1/8 + 1/6

*October 8, 2016*

**algebra**

just multiply the two numbers. But it will not be accurate. It is likely that Idahoans eat more potatoes than the average American.

*October 8, 2016*

**Math**

If the base has dimensions x and y, and the height is z, you want to minimize 5xy + 4*2z(x+y) subject to xyz = 135 Now use your favorite linear programming technique. See whether you can arrive at the solution of 540 at (6,6,15/4) These things usually work out so that two of ...

*October 8, 2016*

**physics**

how long does it take to stop, with acceleration a? 22.5t + 1/2 at^2 = 41 Now, with that t, 22.5 + at = 0 That gives you the value of a. F = ma

*October 8, 2016*

**Projectile Motion Help**

you can see how that formula was achieved if you read the article on trajectory in wikipedia. Maybe your textbook also explains how the formula was derived. In any case, just use it to get your answer!

*October 8, 2016*

**math**

(1/2 + 1/3)x = (1/4 - 1/5)x + 188

*October 8, 2016*

**math**

just solve for x in −0.0055x2 + 1.2x + 10 = 3

*October 8, 2016*

**value**

You want <x,y> such that <8,0>+<5cos30°,5sin30°>+<x,y> = <0,0> then you can get the direction of <x,y>

*October 8, 2016*

**math**

If the folded up edges have length x, then the base is 14-2x The area is thus a = ((14-2x + √2 x)+(14-2x))/2 * x/√2 da/dx = (1-2√2)x + 7√2 da/dx=0 when x = 4+√2 So, the base is 14-(4+√2) = 10-√2

*October 8, 2016*

**math**

After A, 5/8 remain. So, how much did B get?

*October 8, 2016*

**Math**

p = b+12 now write the other equation, and solve for p. hint: last year, their ages were p-1 and b-1

*October 8, 2016*

**physisc**

using g=10m/s^2, we have h - 4t - 5t^2 = 0 h - 20 - 125 = 0 h = 125 m

*October 8, 2016*

**maths**

the two acute angles are complementary. Or, the three angles sum to 180 (as in all triangles)

*October 8, 2016*

**math**

tan(π/4+x/2) = (tan π/4 + tan x/2) ------------------------- 1 - tan π/4 tan x/2 (1+tan(x/2))/(1-tan(x-2)) see where this takes you, and recall the half-angle formula for tan(x/2)

*October 8, 2016*

**maths**

-16t2 + 250t = 500 solve for t

*October 8, 2016*

**Math**

$10.50/hr * 8hr/day * 7day = $(10.50*8*7)

*October 8, 2016*

**Math**

sinh2x =8coshx 2sinhx coshx - 8coshx = 0 2coshx(sinhx-4) = 0 coshx=0 (no solutions) sinhx = 4 x = log(4+√17) http://www.wolframalpha.com/input/?i=sinh2x%3D8coshx

*October 7, 2016*

**Math**

I assume you mean (√3 x^3 + 3√3 y^3 + 5√5 - 3√30 xy Is that right, or did I misinterpret your somewhat murky syntax? And just what is it you want to do with the expression?

*October 7, 2016*

**Math**

lawn only: 45*30 lawn+path: (45+10)(30+10) area of path: (lawn+path)-(lawn only) ratio: duh

*October 7, 2016*

**Algebra**

#1: (-1)(4-c) (-1)(4)+(-1)(-c) -4+c No ideas at all on the others?

*October 7, 2016*

**Trig**

ditto - same song, different verse

*October 7, 2016*

**Trig**

draw your triangle tanA = 2/1 sinA = 2/√5 cosA = 1/√5 sin2A = 2sinAcosA = 4/5

*October 7, 2016*

**Math**

xy = 800 f = x+2y-4 To minimize p, substitute in for x or y, and find where p'=0. Check to be sure it does not matter where the gate is. (on the x side or the y side)

*October 7, 2016*

**MATH**

you might start here: http://www.mathsisfun.com/geometry/ellipse-perimeter.html

*October 7, 2016*

**Algebra**

If |y+4| < 1 then you want all the numbers that are less than 1 unit away from -4. -5 < y < -3

*October 7, 2016*

**Precalculus**

(a) let x=t, y=h(t) (b) as with all parabolas, the vertex is at -b/2a (c) vo is v sinθ now crank it out

*October 7, 2016*

**Physics (PLEASE HELP PRONTO)**

a = g sinθ

*October 7, 2016*

**Calculus**

Review your text section (probably Lagrange multipliers), and see whether you can come up with this solution: http://www.wolframalpha.com/input/?i=minimize+4y%5E2-29x%5E2+subject+to+3x%2By%3D21

*October 7, 2016*

**math**

oops. That figure applies if no girls graduate. If all the girls graduate, then 9/16 + 3/8 = 15/16 may graduate.

*October 7, 2016*

**math**

(9/10)(5/8) = 9/16

*October 7, 2016*

**algebra**

well, 1000m = 1km, so ...

*October 7, 2016*

**Geometry**

it's 3 ft on each side (left&right, top&bottom), so 12 becomes 18, 15 becomes 21. 2(18+21) = 78

*October 7, 2016*

**Math**

either place them all over a common denominator, and then sort the numerators, or convert all to decimal, and then it's easy to sort them.

*October 7, 2016*

**Math**

you want 5+1.00x = 8+0.75x

*October 7, 2016*

**Geometry**

so, which is it - y = -2, or x = -2?

*October 7, 2016*

**math**

use your product to sum formulas: 5 cos4x cos8x = 5/2 (cos12x + cos4x) those are easy, right?

*October 7, 2016*

**Mathematics of growth rate! Need help!**

A*1.05^70 = 3000000 now take logs and solve for logA or, A = 3000000/1.05^70 = (3000000^(1/70)/1.05)^70

*October 7, 2016*

**precalc**

you need to review your ellipses. See whether you can derive these properties: http://www.wolframalpha.com/input/?i=ellipse+x%5E2%2F4%2By%5E2%2F9%3D1 Your other ones should also be evident.

*October 7, 2016*

**math**

just plug in the values and check.

*October 7, 2016*

**Math - Calculus 1**

let f(x) = x^4 - x^2 df = (4x^3 - 2x) dx let x=1, dx=0.1 df ≈ (4-2)(0.1) = 0.2 f(x+dx) ≈ f + df = 0 + 0.2 real value: 0.2541

*October 7, 2016*

**Maths**

R = 14/10 W W = 10/14 R = .714 R so, it's 28.6% less

*October 7, 2016*

**Calculus - Related Rates**

draw a diagram. You can see that if the rocket is at height y, tanθ = y/100 so, sec^2θ dθ/dt = 1/200 dy/dt Now just plug in your numbers and find dy/dt

*October 7, 2016*

**math**

C(n) = C(P(h)) = .35P(h)+1000 = 0.35(375h)+1000

*October 7, 2016*

**maths**

well, you know that the solution to y' + 2y = 0 is y = c e^(-2x) Now just come up with the other part. Besides your class text, take a look at a similar problem here: https://au.answers.yahoo.com/question/index?qid=20100317130334AAtWVqs

*October 7, 2016*

**Physics urgent pleasw**

h(t) = 10.0 - 2.0t - 4.9t^2 now just find t when h=0

*October 7, 2016*

**Math**

as it stands, there are 100 marbles, with blue making up 14% So, for it to be 24%, you need 14/24 * 100 = 58.3 24% of 58 = 13.92 So, 14 marbles would be about 14% of 58

*October 6, 2016*

**calculus**

there are lots of online calculators you can use to verify your answer, such as http://www.wolframalpha.com/widgets/view.jsp?id=174a81e7a9ffb5aed0a790093981aaab

*October 6, 2016*

**math**

true

*October 6, 2016*

**Pre algebra**

The person is 5.5/5 = 1.1 times as tall as the shadow So, the tree is 1.1 * 30 ft tall

*October 6, 2016*

**Math**

well, 3 is prime.

*October 6, 2016*

**Math**

14+x >= 52*0.3048

*October 6, 2016*

**math**

v * 0.74^5 = 300

*October 6, 2016*

**Health**

I plan to practice my tennis drills every day all summer so that I can maintain my #1 seed on the tennis team this year. This is an example of a? 1- performance goal 2- outcome goal my answer is performance goal

*October 6, 2016*

**Science,chemistry**

first step: ask google. I found this in about 10 seconds http://www.gcsescience.com/ex12.htm

*October 6, 2016*

**Merman High School**

what is the net horizontal force on the box? F = ma

*October 6, 2016*

**math**

for x members (assuming you meant 50 centavos, not 0.50 centavos) r(x) = x(100+.5(600-x)) for x < 600 x(100-.5(x-600)) for x > 600 These are really the same function: r(x) = 400x - 0.5x^2 maximum revenue is at x = 400

*October 6, 2016*

**Math**

I suspect you meant 60 ft/s+ ?mi/min 60 ft/s * 1mi/5280ft * 60s/min = (60*60)/5280 = 0.68 mi/min makes sense, since 88 ft/s = 60 mi/hr = 1 mi/min

*October 6, 2016*

**Math**

first of all, they asked for a probability. How many ways to seat all the people? Now, consider all the members of a class as one person. How many ways to seat them now? Do the same for the other classes. (Total ways to seat fused classes) divided by (total ways to seat ...

*October 6, 2016*

**Math**

1.9x10^-1 = 0.00019x10^3 Now just subtract

*October 6, 2016*

**College Physics**

I think you will find that theta = 120 degrees. the angle used is cos(180-theta) There is no way that two 20N vectors pointing in basically the same direction can have a resultant of 20N. You want the short diagonal of the parallelogram.

*October 6, 2016*

**maths**

10/x = tan69°

*October 6, 2016*

**maths plz**

This one looks easy, using trig substitutions, but it is not! Enter your function at the url below and it will show all the messy steps in the solution. http://www.integral-calculator.com/

*October 6, 2016*

**maths**

surely you can integrate cos(2x) dx everything else is just constants.

*October 6, 2016*

**Ashford**

I showed the solutions. As for graphing, just plot the two solutions (points) and shade to the left or right, as appropriate. If that doesn't clear it up, review the use of the number line.

*October 6, 2016*

**Ashford**

4x + 3 < 16 4x < 13 x < 13/4 –2x < 3 -3 < 2x -3/2 < x -3/2 < x < 13/4 This is equivalent to 4x + 3 < 16 AND –2x < 3 Compound inequalities always imply AND. As you wrote it, x can be anything, because it will always be less than 13/4 OR ...

*October 6, 2016*

**Pre-Calculus**

come on. Your turn for some input.

*October 6, 2016*

**Algebra**

√(x^4y) / 4√(x^2y^8) Now, you know that √x^2 = x, so you have (x^2 √y) / 4xy^4 = x√y / 4y^3 Apparently I have not parsed you English words correctly into algebra. Using my symbols (copy/paste), repost so the algebra is clear. At any rate, just ...

*October 6, 2016*

**Trig**

Draw your triangles and quickly see that sinA = -5/√26 cosA = -1/√26 sinB = 2/3 cosB = -√5/3 now just use your sum-of-angles formula for sin(A-B)

*October 6, 2016*

**Math (Continuity)**

f is discontinuous at x = ±2 since the numerator (x) is not zero there, f(x) has vertical asymptotes at x=±2. These are not removable. Removable discontinuities occur where f(x) = 0/0 and the common factor can be removed, such as f(x) = (x-2)/(x^2-4) = (x-2)/(x-2...

*October 6, 2016*

**Math**

12 = 2^2 * 3 36 = 2^2 * 3^2 So, 18 = 2*3^2 and 12 have an LCM of 36

*October 6, 2016*

**Pre-Calculus**

Draw your triangles and see that cosA = 4/5 sinB = 15/17

*October 6, 2016*

**math**

S is a collection of line segments with x- and y-intercepts at (0,1-t) and (t,0) Divide the interval (0,1) into n intervals of width 1/n. Then the two lines at t=k/n and t=(k+1)/n intersect at y = (n-k)(n-k-1)/n^2 So, adding the (k+1)st line adds a thin triangle of base 1/n ...

*October 6, 2016*

**Algebra**

35.00 + 7.25x = 29.00 + 10.50x

*October 6, 2016*

**Physics**

You must not have tried too hard, because I got several hits, such as https://answers.yahoo.com/question/index?qid=20070429182156AAn5Pem which is the exact same problem, but with different numbers.

*October 6, 2016*

**Physics**

try google first I saw several discussions of problems just like yours.

*October 6, 2016*

**calculus**

The distance z from (4,1) to (x,y) is z = √((x-4)^2 + (y-1)^2) = √((y^2/4 - 4)^2 + (y-1)^2) = (1/4)√(y^4-16y^2-32y+272) dz/dy = (1/2)(y^3-8y-8)/√(y^4-16y^2-32y+272) dz/dy=0 when y^3-8y-8=0 y = -2 or y = 1±√5 The minimum z is at y=1+√5...

*October 6, 2016*

**C++**

so, have you compiled and run it? does it do the job?

*October 6, 2016*

**science**

none of the above...

*October 6, 2016*

**Math**

(5/6 ft^2)/(1/2 hr) = (5/6)/(1/2) ft^2/hr = 5/3 ft^2/hr

*October 6, 2016*

**Math mystery number**

7 digits xxxxxxx digit in the ten thousands place is 9 ..9.... The digit in the thousands place is 5 ..95... Now we are down to vw95xyz The hundreds thousands place is the same as the tens place: y=w vw95xwz digit in the hundreds place is 3 times greater than the digit in the ...

*October 5, 2016*

**Algrebra and Math**

f+m = 32 f-1 = 2(m-1) 21 females 11 males check: Fran has 20 female classmates Billy has 10 male classmates

*October 5, 2016*

**Math**

use the Pythagorean Theorem. x^1 + 1^2 = 8^2

*October 5, 2016*

**math**

It looks good, but it's confusing having a club named x and also using x for the no. of months. So, it looks like a typo, but the functions are correct.

*October 5, 2016*

**Math**

you have three quantities: t,r,d and they give you some facts: t = 3r and so on. Then solve for the values.

*October 5, 2016*

**algebra**

(4 x 10^-5)^-6 = 4^-6 * 10^(-5*-6) = 1/4^6 * 10^30

*October 5, 2016*

**Engineering/Physics**

Power = Work/time = Force*distance/time The force, of course, is pressure*area Now just put things into the proper units and it all falls out.

*October 5, 2016*

**calculus**

(a) y(0) = ? (b) this is just a parabola. You know the vertex is at x = -b/2a (c) y=0 at x=? c'mon - don't forget your Algebra I now that you're taking calculus...

*October 5, 2016*

**Math**

dang! count the - signs (not the = signs!)

*October 5, 2016*

**Math**

10x = -5 has solution x = -0.5 -10x = -5 has solution x = 0.5 Now just count the = signs an odd number will be - an even number will be + (on the left side)

*October 5, 2016*

**Pre-Calculus**

clearly B is false at x=π Sec(x) / tan(x) = tan(x) / [tan(x) – cos(x)] (-1)/0 = 0/(0-(-1)) = 0/1 -∞ = 0 I don't think so!

*October 5, 2016*

**College Algebra**

And, note that this maximum area occurs when the fencing is equally split among lengths and widths.

*October 5, 2016*

**geometry**

h(t) = -16t^2 + 60t = 4t(-4t+15) h(2) = 4*2(-4*2+15) = 8(7) = 56 now just plug in 3.75 for t. Or, note that h(t) = 0 when -4t+15=0 t = 15/4 = 3.75 so, what does that mean?

*October 5, 2016*

**Math**

Divide the volume (L) by the net fill rate (L/min): 100/(60/5 - 14/2) = 20 min

*October 5, 2016*

**College Algebra**

look at the units. You have mi/gal mi/hr You want to use those to end up with miles in terms of hours. mi/hr * hr = mi d(t) = 65t mi/(mi/gal) = gal n(d) = d/25 d(t) is miles driven in t hours n(d) = gallons used in d miles = gallons used in t hours. (n◦d)(t) = n(65t) = ...

*October 5, 2016*

**maths polynomial need help**

(8m^2-24m-3+3√17)/4 * (8m^2-24m-3-3√17)/4

*October 5, 2016*

**math**

256πh/3 = 420 solve for h

*October 5, 2016*