Saturday
November 22, 2014

Posts by Steve


Total # Posts: 26,900

math
35 in to the square root of 2 ? Do you mean 35 in^2 If so, that's the power 2, not to the √2 Anyway, that's not enough information. Even if you restrict the rectangle to integer dimensions, it could be 1x35 - perimeter=72 5x7 - perimeter=24
October 15, 2014

Geometry
I guess C is the midpoint of AD. if so, then 5x-8 = 16-3x x = 3 Now you can find the lengths. If not, then you need to provide more details.
October 14, 2014

math
1/k + 1/7 = 1/4 Now just solve for k.
October 14, 2014

Geometry
Many people use m<A to mean "measure of angle A" Also <= or >= for less/greater than or equal
October 14, 2014

Geometry
interior is 180-x # sides is 360/x
October 14, 2014

Pre-Calc/Trig...
nope. No shapes get deformed or warped, or scaled. The whole rigid system is just moved upward.
October 14, 2014

Math
A is in QII, so cosA = -5/13 B is in QIV, so cosB = 24/25 Now, you have cos(A-B) = cosAcosB + sinAsinB ...
October 14, 2014

Chemsitry
How many grams of ice at -24.3∘C can be completely converted to liquid at 23.9∘C if the available heat for this process is 4.82×103kJ ? For ice, use a specific heat of 2.01J/(g⋅∘C) and ΔHfus=6.01kJ/mol.
October 14, 2014

Foundations and Pre-Calculus Math 10
v = 1/3 pi r^2 h so, pi/3 r^2 (3) = 30 r^2 = 30/pi r = ...
October 14, 2014

Pre-Calc/Trig...
both correct
October 14, 2014

Perimeter and Area
did you plot the points? The first one is clearly a square. So, now what is your choice? The second, assuming no typos, has duplicate points, so it is just a short vertical line.
October 14, 2014

math
Since the vertex is set at (0,0), you have a parabola y = ax^2 where y(200) = 100 a*40000 = 100 a = 1/400 y = 1/400 x^2
October 14, 2014

Math
1 kg = 1000g 603kg = 603*1000 g
October 14, 2014

Math
clearly a cube with side equal to the diameter of the sphere. So, since for a sphere, v = pi/6 d^3, just plug in your numbers and solve for d.
October 14, 2014

Math 116
since a=lw, your new area is (1.1l)(0.9w) = 0.99 lw So the area has decreased by 1%
October 14, 2014

Math 130
sure you can find the desired measures. Just consult your text for the relevant formulas and examples.
October 14, 2014

Math
Extend the sides to meet at point E. Since each exterior angle is 60°, angle BCE = CBE = 60° So, now you only have to find the third angle (angle E) of triangle BCE.
October 14, 2014

c programming
wow. Things would have been have been a lot more compact if you had used an array of month days: modays[12] = [0,31,28,31,30,...] and then just adjusted the 28 as needed for the leap year.
October 14, 2014

math
1/2 < x/8 multiply by 8 on both sides: 4 < x
October 14, 2014

Algebra
If there are x 4-seaters, and y 10-seaters, then x+y <= 52 4x + 10y >= 280 see the solution set at http://www.wolframalpha.com/input/?i=solve+x%2By+%3C%3D+52%2C+4x+%2B+10y+%3E%3D+280%2C+x%3E%3D0%2C+y%3E%3D0
October 13, 2014

math
since each equation is a straight line, each has exactly one solution. Think on it. A solution is where the graph intersects the x-axis. Two distinct lines intersect in exactly one point, unless they are parallel.
October 13, 2014

pre-calculus
revenue is room-charge * #rooms, so R(x) = (700+14x)(550-7x) That's just a parabola, and you can easily find its vertex.
October 13, 2014

Algebra
well, duh: 15 + .5x = 25 + .25x Now just solve for x...
October 13, 2014

Math
well, you have the formula: v = (3+2i)(4-i) = 14+5i
October 13, 2014

Algebra
Start from 110 feet away, a person on a bicycle rides toward a checkpoint a nd then passes it. The rider is traveling at a constant of 30m feet per second. The distance between the bicycle and the checkpoint is given by the equation d=(110-30t). At what times is the bike 40 ...
October 13, 2014

Algebra 2
If we call the equations #1,2,3 then subtract #1 from #2 and #3 from #3 to get 96a + 8b = 2 84a + 6b = 0 So, 6b = -84a, meaning 8b = -112a So, 96a - 112a = 2 -16a = 2 a = -1/8 now use that to get b = 7/4 c = 7 It would have been nice for you to have shown your work. Oh well, ...
October 13, 2014

College Physics
Since all her KE is converted to PE, 1/2 mv^2 = mgh so, 1/2 * 39.7^2 = 9.81h Note that the angle of incline makes no difference.
October 13, 2014

Algebra help
If you mean to say f(x) = 5x-1, then you are correct.
October 13, 2014

Math
as was already posted, 2cos^2 θ
October 13, 2014

Intro to Programming PT1420
nothing - there is a syntax error.
October 13, 2014

Math
If the intensity on Earth is x, then since Id^2 = k is constant, 9140*.387^2 = 1x As for rate of change, who says it's changing?
October 13, 2014

Math
Yes, I can.
October 13, 2014

Physics
If she has mass m, then she is part of the total mass. So 120 = (8.4+m)(1.7) Now just solve for m.
October 13, 2014

physics please help
√(4.57^2 + 4.74^2) / 5.76 = 1.14 m/s^2 I expect you can figure the direction.
October 13, 2014

vp manthata secondary school
Since v = πr^2h 42 = 5πr^2 r^2 = 42/(5π) r = √(42/(5π))
October 13, 2014

College Math
(a) a circle always gives the largest area for a given perimeter. Among rectangles, a square gives the largest area. (b) 1: p = 120/4 = 30 ft area: 7.5^2 = 56.25 2: c = 120/5 = 24 area: = 45.8 So, the expensive fencing reduces the circular area for planting.
October 13, 2014

MATH 101
15x^2(2x + 3) + 41x(2x + 3) + 28(2x + 3) (15x^2+41x+28)(2x+3) (3x+4)(5x+7)(2x+3)
October 13, 2014

MATH 101
40(30+41t+7t^2) 40(5+t)(6+7t)
October 13, 2014

math
(10+4)(6+4)-(10)(6)
October 13, 2014

Math
(4/5)(m-m/12) = 704 (4/5)(11/12)m = 704 11/15 m = 704 m = 704 * 15/11 m = 960
October 13, 2014

Math
After taxes, a $1 items sells for $1.085 So, the items sold account for all the extra money: (1065.95-122.00)/1.085 = 870 That's how many items were sold.
October 13, 2014

Math-Urgent help please.
4/52 * 4/51 = 0.00603 so, knowing that, choose 2
October 13, 2014

Kennedy king
(1+r)^10 = 2.0 1+r = 2.0^0.1 r = 2.0^0.1 - 1 So, to grow by a factor of 1.5, will take (1+r)^t = 1.5 2^.1t = 1.5 .1t = log1.5/log2 t = 10(log1.5/log2) = 5.85 years Depending on when interest is posted, it could take up to 6 years to see the $15K
October 12, 2014

English
Thank you
October 12, 2014

English
Jack London's works did not enjoy popularity until after his death. a- true b- false My answer is false
October 12, 2014

English
No mam just the way I wrote it. Could they be talking about gold from Alaska?
October 12, 2014

English
I agree but that is the way the homework question was stated.
October 12, 2014

English
How did gold get to California? a- dog sled b- steamship c- by airplane My answer is steamship
October 12, 2014

English
How much gold , arriving in San Francisco, triggered the gold rush? a- 500 lbs b- 1 ton c- 2 tons My answer is 2 tons
October 12, 2014

geometry
a vertical line has equation x=h for some h. You have the point (5,6), so x=5 Similarly for horizontal lines and y.
October 12, 2014

Calculus
since h = 2r, r = h/2 v = pi/3 r^2h = pi/12 h^3 So, dv/dt = pi/4 h^2 dh/dt When h=6, we have 25 = 9pi dh/dt Now just do the math
October 12, 2014

math
Yeah, that's the problem when the assumptions aren't explained. Another way would be to assume the bill included the tax, so the actual meal only cost 56.25/1.075, and the tip was calculated on that basis. There'd be no reason to even mention the tax if it weren&#...
October 12, 2014

math
c'mon. You get a bill for $56.25 You tip 15%, which is 56.25 * .15 You add that to the bill, so your final amount is 56.25 + 56.15 * .15 = 56.25(1+.15)
October 12, 2014

math
Depends - do they tip on the whole bill? Most folks do. In that case, they spent $56.25 * 1.15 if the tax is included in the bill, as is usually the case.
October 12, 2014

geometry
I just did! The line AB has slope -5. So, any line parallel AB also has slope -5. The line you want is thus y-1 = -5(x+2)
October 12, 2014

geometry
a line with slope m containing (h,k) is y-k = m(x-h) Now plug in your values.
October 12, 2014

precalc
220/360 of the full circumference
October 12, 2014

Algebra
clearly, for a physical cube, the sides cannot be zero or negative. So, the domain is all positive real values: s > 0 So, the range, 6s^2, is also all positive reals, A > 0 Your teacher has further restricted the domain to s >= 5 So, the range 6s^2 >= 150 In ...
October 12, 2014

Algebra
the domain of all polynomials is all real numbers. Naturally, in the real world, only positive time makes sense, so the domain here is just t >= 0 What planet is this ball on? gravity on earth wold make the function H(t) = 72t - 16t^2 Find the vertex of that parabola. That ...
October 12, 2014

college intermediate
If x are taking both biology and Spanish, then 36+52-x = 200-126 x = 14 So, 36-14=22 are taking biology but not Spanish. That should get you started.
October 12, 2014

Math
If x = |x|, then x is positive If x-2 ≠ |x-2| then x-2 is negative That should get you started.
October 12, 2014

Algebra 2 Answer Check (Reiny)
You have done a horizontal compression
October 12, 2014

Algebra
f+s+t = 490 3f+2s+t = 878 s = 4+2t Now you can solve for f,s,t.
October 12, 2014

Math
as written, it is 0 with remainder x-6 I think you mean (10x^4-50x^3-800)/(x-6) See the details at calc101.com click on the "long division" button.
October 12, 2014

Math
If a rectangular array, 6x+6y = 750 a = 4xy = 4x(750-6x)/6 = 500x - 4x^2 max area at x = 62.5, y=62.5, large pen = 125x125 If a linear array, 8x+5y = 750 a = 4xy = 4x(750-8x)/5 = 600x - 32/5 x^2 max area at x=46 7/8, y=75, large pen = 186.5x75 As usual, the square provides the...
October 12, 2014

AP CALC. AB
#1 The particle is at rest when its velocity is zero. So, we need dx/dt=0 dx/dt = 6t^2-26t+22 So, solve for t #2 moving left ==> velocity is negative dx/dt = 16t^4-75t^2+60 So, solve for dx/dt < 0 #3 greatest speed is max velocity. That means dx/dt has a max, so d^2/dt^2...
October 12, 2014

Algebra
If the short leg is x, we have x^2 + (3x+13)^2 = (3x+14)^2 x = 9
October 11, 2014

math
the same as the number of places the decimal point has shifted.
October 11, 2014

math
Any value x such that 3.5-3.5 < x < 3.5+3.5
October 11, 2014

Math (Algebraic Proving)
Draw a diagram of an ellipse. Draw diagonals from (0,b) to (-c,0) and (c,0) The definition of such an ellipse is that the sum of the distances from a point to the foci is constant, and = 2a where a,b,c are described above. Just google any explanation of the definition of an ...
October 11, 2014

math
1.14c = s c = s/1.14 = .877s so, there is a 12.3% markup based on selling price.
October 11, 2014

Algebra word problem
clearly the equation of the arch is y = 20 - ax^2 y(18) = 0, so a = 0.0617 So, y = 20-0.0617x^2 y(9) = y(-9) = 15
October 11, 2014

Math (Word Problem)
The original square has side of length x. So, (x-8)(x-8)(4) = 576
October 11, 2014

College Algebra
rsx^2 + (rt+s^2)x + st = 0 Now just use the quadratic formula: x = [-(rt+s^2)±√((rt+s^2)^2 - 4rs^2t)]/2rs = [-(rt+s^2)±(rt-s^2))]/2rs = (-rt-s^2+rt-s^2)/2rs = -s/r or = (-rt-s^2-rt+s^2)/2rs = -t/s
October 11, 2014

HELP!! Algebra
the smaller the divisor, the larger the quotient. 12/6 = 2 12/4 = 3 12/3 = 4 12/2 = 6 12/1 = 12 12/(1/2) = 24 because there are 24 halves in 12 wholes. When dividing by a number less than 1, the quotient is larger than the dividend. Again, if a slice of pie is 1/6 of the pie, ...
October 11, 2014

Math help
yes. when dividing, it is the same as multiplying by the reciprocal.
October 11, 2014

computer science
64(mod 18) = 10 because 64 = 3*18 + 10 32+10 = 42
October 11, 2014

Math
ln(x+1)/ln(x-1) = 2 ln(x+1) = 2ln(x-1) x+1 = (x-1)^2 x+1 = x^2-2x+1 x^2-3x = 0 x = 0 or 3 check: ln(1)/ln(0) = 2 Not a solution ln(4)/ln(2) = 2 ln(2^2)/ln(2) = 2 2ln2/ln2 = 2 yes
October 10, 2014

Math
log(sqrt(x^2+1)) = 1/5 1/2 log(x^2+1) = 1/5 log(x^2+1) = 2/5 x^2+1 = e^(2/5) ...
October 10, 2014

Math, Help Please IF you can
(a) 5^2 = 25, and we want (3-h)^2 = 25 so, 3-h = ±5 g(x) = (x+2)^2 or (x-8)^2 (b) g(x) = x^2+16 (c) shift right 2 is (x-2)^2 Since (3-2)^2 = 1, g(x) (x-2)^2 + 24
October 10, 2014

math
or, (1 + 3 1/4) : (1 1/4 + 3 1/3) = (4/4 + 13/4) : (15/12 + 40/12) = 17/4 : 55/12 = (17*12):(4*55) = 204:220 = 51:55
October 10, 2014

Math
shift first by 4: x^3+4 then reflect: -(x^3+4) = -x^3-4 -x^3+4 is what you get when you reflect, then shift
October 10, 2014

Math
If m(n) = n^2/2 m(n-1.2) = (n-1.2)^2/2
October 10, 2014

Algebra 2
g(x) = f(x/(3/2)) = f(2/3 x) = |2/3 * 2x| - 3 = |4x/3| - 3 See http://www.wolframalpha.com/input/?i=plot+y%3D|2x|-3%2C+y%3D|4x%2F3|+-+3
October 10, 2014

Algebra 2
g(x) = f(x)/4 = |x/2| - 3/4 See http://www.wolframalpha.com/input/?i=plot+y%3D|2x|-3%2C+y%3D|x%2F2|+-+3%2F4
October 10, 2014

math 11
25000(1+.033)^4
October 10, 2014

Math help 1 question!!!!!!!!
C is correct. A is also, but if they are implying a square root of an integer, then it is false. After all, a/b = √(a^2/b^2) whatever values a and b have.
October 10, 2014

Science
well, the present date is 2014 So, what is 2014-(906±35)?
October 10, 2014

Math
-4 - √(4-x) = 6 -√(4-x) = 10 4-x = 100 x = -96 Unfortunately, this is not a solution, since -4 - √(100) = -4-10 = -14, NOT 6 √100 is NOT ±10. √100 is 10. So, the equation as written has no real solutions
October 10, 2014

Math
Just use Heron's formula: A = √((23)(23-12)(23-16)(23-18))
October 10, 2014

Math
If the angle is θ, the law of cosines says that 36^2 = 15^2 + 25^2 - (2)(15)(25) cosθ
October 10, 2014

math
Assuming that by "updated marks" you mean your average test score, and assuming that the tests are of equal weight, your average is just the average of the scores: (36+53)/2 Why do you append the sentence "It's my first test."? You just told us your ...
October 10, 2014

math
what, no calculator? 2(13.7) = 27.4 27.6/9.8 = 2.7959 √2.7959 = 1.672
October 10, 2014

math
present age of father = x 6 times the age of son = 6y so, we have x = 6y+5y I suspect you meant five more than If so, x=6y+5 If you meant five times as much as, then x=5*6y
October 10, 2014

Math Help
Not much engineering here. Must have been a test post.
October 10, 2014

How long will it take the investment to double?
The initial amount does not matter. You want e^0.048t = 2 t = ln2/0.048 = ?
October 10, 2014

math
f+200m = 122 f+189m = 118.15 Now subtract; the f's go away and you have 11m = 3.85 m = 0.35 Now, I expect you can find f, the flat fee.
October 10, 2014

physics
starting momentum: 1500*36 final momentum: 1500*72 That gives you momentum in kg-km/hr you probably want it in kg-m/s, so you need to convert km/hr to m/s.
October 10, 2014

algebra2
I don't see any fractions. How can there be a denominator?
October 10, 2014

calculus
I think you mean find the second derivative. Do you mean partial derivatives? There are three. Fx = 2e^y + 3ye^-x Fy = 2xe^y - 3e^-x Fxx = -3ye^-x Fyy = 2xe^y Fxy = Fyx = 2e^y + 3e^-x
October 10, 2014

Pages: <<Prev | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | Next>>

Search
Members