Tuesday

April 21, 2015

April 21, 2015

Total # Posts: 30,685

**Math**

If I know all 3 angles of a right triangle and the hypotenuse how do I figure out the short side length of the triangle?
*April 3, 2015*

**6th Grade Math ASAP!!!**

you're right -- it is complex. Especially so since you don't seem to have any questions about it.
*April 3, 2015*

**Math**

rotation through 180° changes both signs. So, (3,-5) -> (-3,5) Did you actually plot your solution? You would see that it was nowhere near the rotated point. an equilateral triangle has axial and rotational symmetry.
*April 3, 2015*

**programming**

for i=1 to 100, read a(i) read n for i=1 to 100, {if a(i)==n, print i} n = a(1) for i=2 to 100, if a(i)>n, n=a(i) print n See whether you can use the above section to repeatedly find the smallest element and place it in the next position. That is, sort the array.
*April 3, 2015*

**Algebra**

I don' see no steenking inequalities! For the equations, 6y = 9(x-6) 3(2y+5x) = -6 6y = 9x-54 6y+15x = -6 so, since we have 6y in both equations, set them equal: 9x-54 = -6-15x 24x = 48 x = 2 now you can find y.
*April 3, 2015*

**6th Grade Math Help**

excuse me? Every parallelogram is a regular parallelogram. They all have two sets of parallel sides. Pick any side and call it a base. The altitude is the perpendicular distance between that base and the parallel side.
*April 3, 2015*

**6th Grade Math Help**

the slanted side cannot be less than the height. That's like saying the hypotenuse of a right triangle is shorter than one of the legs. At any rate, if you can figure out what the height is (the perpendicular distance between two of the parallel sides), then the area is ...
*April 3, 2015*

**algebra**

you can go the e^kt route, but it's more transparent to use base 2, since we're talking about half-lives. 2^-1 = 1/2, so A = Ao*2^(-t/10) after 5 years, you have A = 20*2^(-5/10) = 14.14g Of course, since 2 = e^ln2, that means you could use (e^ln2)^(-t/10) = e^(-t*ln2/...
*April 3, 2015*

**math**

you are correct 62kg/ft^3 / 8.3kg/gal = 7.46gal/ft^3
*April 3, 2015*

**math**

well, xy=k, so 12*6 = k
*April 2, 2015*

**Math 222**

I assume you are trying to find excluded x values. If so, you are correct. You know, we like to try and help find answers. Don't make us come up with the questions, too!
*April 2, 2015*

**Math 222**

because I have been exposed to similar careless mistakes displayed by others. Tell me. Just looking at your posting, could you easily tell what was being asked? The questions and solutions are all mixed up together.
*April 2, 2015*

**Math 222**

Leaving aside the virtually impenetrable formatting, your math appears to be ok.
*April 2, 2015*

**forth**

you really had a hard time coming up with 27? Did you try just listing the numbers between 22 and 30 and looking at them?
*April 2, 2015*

**algebra**

LCD(20,30) = 10, so the desired LCD is 1/10 x^3y^4 Nothing larger can be factored from both items.
*April 2, 2015*

**math**

is the swap simultaneous, or did Rich give her his 1/6 after he received her 1/4?
*April 2, 2015*

**Steve/Ms.Sue**

since the triangle is equilateral, the radius of the circle is 18. so, your area is 5/6 of a circle plus the area of the triangle, which is 18^2/4 √3 = 81√3
*April 2, 2015*

**Algebra 1**

7-24-25 is one of the standard integer-sided right triangles. Use the Pythagorean Theorem to verify that. Just FYI, it's often helpful to remember the others: 3-4-5 5-12-13 8-15-17 7-24-25 9-40-41
*April 2, 2015*

**Algebra 1**

A right triangle's legs are 7 inches and 24 inches. What is the measure of the angle opposite the 24 in leg?
*April 2, 2015*

**Math**

well, 3 lbs is 48 oz. ...
*April 2, 2015*

**math**

a=2 http://www.wolframalpha.com/input/?i=solve+%7B%7B1%2C3%2C2%7D%2C%7B2%2C-1%2C-3%7D%2C%7B5%2C2%2C1%7D%7D*%7B%7Ba%7D%2C%7Bb%7D%2C%7Bc%7D%7D%3D%7B%7B3%7D%2C%7B-8%7D%2C%7B9%7D%7D
*April 2, 2015*

**Algebra 1**

how can you possibly not be sure? Look at your calculation! If the side you want is x, then x/10 = sin 40°
*April 2, 2015*

**Algebra 1**

A right triangle has a 40 degree angle. The hypotenuse is 10cm long. What is the length of the side opposite the 40 degree angle? I got 6.4cm but not sure of how I got it.
*April 2, 2015*

**Precalc**

(a) when 5t + 17t = 6*5280 (b) when 5t = √(5000^2+(6*5280-17t)^2)
*April 2, 2015*

**trig**

well, you could start out with a little algebra: cos^4-sin^4 = (cos^2-sin^2)(cos^2+sin^2) so you have cos^2-sin^2 ...
*April 2, 2015*

**MATH**

since the triangles are similar, the angles are all the same as in ABC.
*April 2, 2015*

**Calculus**

37y^36 y' = 8x^7 y' = 8/37 x^7/y^36 Now, since y^37 = x^8, y^36 = (x^8)^(36/37) y' = 8/37 x^7 x^(-288/37) = 8/37 x^(-29/37) Doing it explicitly, using the power rule, y = 8/37 x^(8/37 - 1) = 8/37 x^(-29/37) Kind of a dumb problem to use to illustrate implicit ...
*April 2, 2015*

**math**

2l + 2πr = 660 a = 2lr + πr^2 = 2(660-2πr)/2 * r + πr^2 = r(660-2πr) + πr^2 = 660r - πr^2 Now just set da/dr=0 to find r, then l.
*April 1, 2015*

**calculus**

To answer the 1st question, just plug in t=2 and solve for k: 68+30.6e^(-2k) = 96.6 Now just use the amended formula for the rest. If you get stuck, come on back and show us whatcha got so far.
*April 1, 2015*

**Geometry**

since PQR = 60°, PQX = 30° So triangle PQX is an isosceles triangle with base angles of 30° and base=12 Thus, its altitude is 6/√3 and its area = 36/√3 = 12√3
*April 1, 2015*

**Algebra2 Help please**

There are 10 scores. The 90th percentile is the score with 9 below it. Similarly, the 30th percentile is the score with 3 below it. Did you check the related questions below? Since the 3rd score is 105 and the 4th score is 113, I guess any score x where 105 <= x < 113 ...
*April 1, 2015*

**geometry**

√(250^2+200^2) = 50√(5^2+4^2) = 50√41 = 320.2
*April 1, 2015*

**Jonase the moocher**

c'mon. just sub in 3x^2 + 4x(2-x) + (2-x)^2 = 6 Now just collect stuff and solve the quadratic equation.
*April 1, 2015*

**Mathematics - garbled**

Want to fill in the missing words?
*April 1, 2015*

**Sciene**

looks like you need to gather your materials and stop complaining.
*April 1, 2015*

**Math**

(x,y) -> (x-4,y+1)
*April 1, 2015*

**Exponential Equations**

Just solve for t in 2500(1+.0275)^t = 3500 1.0275^t = 1.4 t log1.0275 = log1.4 t = log1.4/log1.0275 = 12.4
*April 1, 2015*

**Maths**

see the previous solution in the related question below.
*April 1, 2015*

**MATH**

can you say homework dump? I knew you could. Still, here's a freebie. Show some effort on the rest, ok? v = (48-16)(36-16)(8) = 5120 m^3 a = (48-16)(36-16) + 2((48-16)(8) + (36-16)(8)) = 1472 m^2
*April 1, 2015*

**Algebra 2**

first off, it's theta, not treta! cot(θ-π/2) = (1+cot(θ)cot(π/2))/(cot(π/2)-cot(θ)) = -1/cotθ = tanθ
*April 1, 2015*

**Math**

looks good to me
*April 1, 2015*

**algebra**

avg velocity is (total distance)/(total time) so, that would be (s(4)-s(2))/(4-2)
*April 1, 2015*

**precalculus help**

z = 2cis(2π/3) ∛z = ∛2 cis(2π/9)
*March 31, 2015*

**precalculus**

sin2θ = 2sinθcosθ sin(θ+π/2) = cosθ cos(θ+π/2) = -sinθ play around with that some, and verify your algebra with the graph: http://www.wolframalpha.com/input/?i=plot+r%3D2sin2%CE%B8
*March 31, 2015*

**Math**

that's matrices What do you mean by the value? The value of a matrix is the matrix.
*March 31, 2015*

**math**

assuming some invisible x's, you are correct.
*March 31, 2015*

**math**

If he answered all 12 questions, and got x of them correct, then 5x - 2(12-x) = 39
*March 31, 2015*

**Mathematics**

what do you get for the range of distance and speed?
*March 31, 2015*

**geometry**

since the vertex angle is obtuse, it is the largest angle. So, the two smaller angles are both 2x.
*March 31, 2015*

**algebra**

well, what is (2+i)^2 ? 2^2 + 4i + i^2 = 3+4i Looks like you got it right.
*March 31, 2015*

**Math**

The interest part would be P(1+r)^t - P
*March 31, 2015*

**math**

huh? what does that mean??? Your alleged question is so poorly written it's incoherent. As I said, just plug in your numbers: da/dt = √3/2 * 12 * √3 = 18
*March 31, 2015*

**math**

a = √3/4 s^2 da/dt = √3/2 s ds/dt Now just plug in your numbers
*March 31, 2015*

**Calculus 1**

use the chain rule if u = x^2+2, then you have f = 1/3 u^(3/2) df/dx = df/du * du/dx Now it's easy, right?
*March 31, 2015*

**basic programming principles**

print select code { S: Single D: Divorced M: Married W: Widowed else: Incorrect }; use syntax appropriate for your programming language.
*March 31, 2015*

**BUS math**

35 = .21p p = 166.67 check: the markup is 131.67 131.67/166.67 = 0.79
*March 31, 2015*

**basic programming principles**

prompt for name, dept, salary read name, dept, salary bonus = (dept = 3) : 850 : 700 gross = salary+bonus net = gross * 0.75 display name, net
*March 31, 2015*

**physics**

None - she is sitting drinking a Mai Tai and watching the man do the lifting. But, work = Force*distance = mass*g*distance
*March 31, 2015*

**Trigonometry (identities)**

√(sin^4xcosx) * √(cos^3x) = √(sin^4x cos^4x) = sin^2x cos^2x = 1/4 sin2x
*March 31, 2015*

**Trigonometry (identities)**

sin(α+β)+sin(α-β) = sinα cosβ + cosα sinβ - (sinα cosβ - cosα sinβ) = 2cosα sinβ I suspect a typo. I will use (-8cosxsinx+4cos2x)^2 + (4cos2x+8sinxcosx)^2 = (-4sin2x+4cos2x)^2 + (4cos2x+4sin2x) = 4^2((cos2x-...
*March 31, 2015*

**Math**

if you say so.
*March 31, 2015*

**MATH**

716-{(1950/5 of 3)-(4+217/7)} of just means times, so you have 716-{(1950/5 * 3)-(4+217/7)} 716-{(390*3)-(4+31)} 716-{1170-35} 716-1135 -419
*March 31, 2015*

**physics**

(9.6*10^-6 * 6.24*10^18)/(29*4*10^23) = ?
*March 31, 2015*

**Maths**

1 - (4/9 + (2/5)(5/9)) = 1/3
*March 31, 2015*

**Maths**

2/5 rotten means 3/5 fresh 3/5 * 5/8 = 3/8 kg
*March 31, 2015*

**This is nothing to do with school**

3a+c = 30 a+3c = 22 take it from there...
*March 31, 2015*

**ABC**

drop the stone and time how long it takes to hit the ground. Actually, that does not measure the height of the building. He infers the height from the time taken. To actually measure the height, he'd probably have to measure the width of the stone and then count how many ...
*March 31, 2015*

**science**

Vx = 9.8 Vy = √(2as) = √(2*9.8*100) = 44.27 final v = √(Vx^2 + Vy^2)
*March 31, 2015*

**calculus**

cos2x = secx 2cos^2(x)-1 = 1/cosx 2cos^3(x) - cosx - 1 = 0 you will probably need to use a graphical or numeric method to solve this. However, you know that cos2x never gets more than 1, and secx never gets less than 1. So, you will need cos2x = secx = 1 or cos2x = secx = -1 ...
*March 31, 2015*

**Algebra**

(a) look good (b) the friend
*March 31, 2015*

**algebra**

since x is proportional to y, x = ky That is, x/y is constant. So, 12/16 = 1/y
*March 31, 2015*

**chemistry**

well, PV = nRT plug in your numbers and solve for P.
*March 30, 2015*

**Calculus**

profit = revenue-cost revenue = 20*4πr^2 = 80πr^2 cost = 800*4/3 πr^3 = 3200/3 πr^3 so, profit = 80πr^2 - 3200/3 πr^3 max profit when 160πr - 3200πr^2 = 0 160πr(1-20r) = 0 r = 1/20 ft looks like marbles make the most money.
*March 30, 2015*

**math**

24*72 = 24*3*24 = 3*24^2 so, its root is 24*root(3)
*March 30, 2015*

**5th grade (math)**

no idea. How big is the lawn?
*March 30, 2015*

**English**

my answer is B
*March 30, 2015*

**English**

Which of the following moments in "The Most dangerous Game" represents an example of foreshadowing? a-Whitney & Rainsford';s discussion about hunting b- Rainsford's observing the gate of the chateau c- Whitney's comment about the light of Rio?
*March 30, 2015*

**math**

see some of the related questions below.
*March 30, 2015*

**math - eh?**

How did Kayla give away 3/2 beads? Try posting the question as you received it.
*March 30, 2015*

**Calc.**

I must be missing something. Clearly the minimum length of fold is achieved when the paper is folded in half, so the upper right corner touches the lower right corner. Then the fold is straight across, and is 8" long. Any diagonal fold will be longer. Of course, I have no...
*March 30, 2015*

**Calculus**

If the distance is x from P, then the cost is c(x) = 1.5√(x^2+25) + (10-x) dc/dx = 1.5x/√(x^2+25) - 1 = [1.5x - √(x^2+25)]/√(x^2+25) dc/dx=0 when the numerator is zero, or 1.5x = √(x^2+25) 2.25x^2 = x^2+25 1.25x^2 = 25 x^2 = 20 x = 2√5
*March 30, 2015*

**Algebra**

(r^-3s^1/3)^6 / (r^7 s^3/2) r^-18s^2 /(r^7 s^3/2) r^-11 s^1/2 or s^1/2 / r^11
*March 30, 2015*

**Algebra 2**

#1 add the two equations to eliminate y^2: 2x^2=18 x = ±3 #2 multiply by 3 to get 3x^2+3y^2=24 since 3x^2 = 5y^2, 8y^2 = 24 y^2 = 3 #3 just sub in directly: 3x^2-2y^2 = 24 3x^2 - (1/2)(2y)^2 = 24 3x^2 - (1/2)(3x)^2 = 24 6x^2 + 9x^2 = 48 15x^2 = 48 x^2 = 16/5
*March 30, 2015*

**Algebra HELP ASAP**

w(2w-1)=10 2w^2-w-10 = 0 (2w-5)(w+2) = 0 w = 5/2 so, the length is 4
*March 30, 2015*

**calculus**

the distance from (x,y) to (4,-3) is √((x-4)^2 + (y+3)^2) = √((x-4)^2 + ((2x+7)/4+3)^2) = √5/4 (4x^2-20x+61) This has a minimum at x = 37/10 So, the point is (37/10,-18/5) Or, you can consider the perpendicular line through (4,-3). It is y+3 = 2 (x-4) This ...
*March 30, 2015*

**Math**

1x10^-2 = 1/100 lbs = 4/25 oz seems a bit light, but it's a lot closer than 10^-20 = 1/100000000000000000000 lbs!!!
*March 30, 2015*

**calc**

f is increasing where f' > 0 since the even powers are always positive, f'>0 where x-3 > 0 and x-4 > 0 so, that would be (3,4)U(4,∞)
*March 30, 2015*

**Middle Math**

Nope. too many zeros, and wrong number 6E0 = 6 6E-1 = 0.6 ... 6E-7 = 0.0000006 You wrote 7E-8
*March 30, 2015*

**math**

if the discriminant is zero, there is only one root, hence only one point of intersection. positive, two roots negative zero roots Incidentally, you'd better check your discriminant. If you graph y=x+5, you will see that it intersects in two points, not 1. http://www....
*March 30, 2015*

**calculus**

see the related questions below
*March 30, 2015*

**Math**

y = x^(e^x) lny = e^x lnx 1/y y' = e^x(lnx + 1/x) y' = x^e^x * e^x (lnx + 1/x)
*March 30, 2015*

**Calculus**

you have the functions. Just plug in the values.
*March 30, 2015*

**Calc**

(a) dC/dx (b) and (c) are just plug and chug
*March 30, 2015*

**math help**

come on. You have the formula. Just solve n^2+n-1 = 2549 Hint: it's not -51
*March 30, 2015*

**math help**

check the differences: 4,6,8 I suspect that the next terms are 19+10=29 and 29+12 = 41 you plug in 3 pairs of values into a general quadratic y=ax^2+bx+c and you get a+b+c=1 4a+2b+c=5 9a+3b+c=11 a=1, b=1, c=-1 and get Tn = f(n) = x^2+x-1 Or, you can recall that 1+2+3+...n = n(...
*March 30, 2015*

**Mathematics**

((5*.60)+.80)/6 = 63.3% You didn't say whether the tests were weighted, so I'm not sure what the 200 points mean.
*March 30, 2015*

**Algebra**

after t minutes, you want 30+25t = 300-20t
*March 30, 2015*