Tuesday
August 30, 2016

Posts by Steve

Total # Posts: 42,911

Math
well, 8012 = 4*2003 now just keep going
August 29, 2016

Pre-Calculus
distance = d rt = (3/4 r)(t+12) rt = 3/4 rt + 9r 1/4 rt = 9r t = 36 So, it takes 36+12=48 minutes to bike home
August 29, 2016

algebra
|d-5.000| <= 0.001
August 29, 2016

Geometry
how is 30.0 to the nearest 0.0001? Maybe you meant nearest 0.0001m, not mm?
August 29, 2016

math
when all you have is $100 bills, you gotta round to hundreds.
August 29, 2016

Math
I vote for 3^4^5 ≈ 10^488
August 29, 2016

Math
clear fractions, or cross-multiply 3(5x+6) = 7(3x-9) 15x+18 = 21x-63 ...
August 29, 2016

algebra
2x-4 = 22 2x = 26 x = 13 same way for the other
August 29, 2016

Math
P(q) = 1/3 P(n|d,q) = 2/9 P(n|d,n|d) = 4/9 So, what do you think? the 1st probability means that if the 1st coin is a quarter, the 2nd does not matter.
August 29, 2016

geometry
tb = tu+ub -3 = 1-x + 4x+17 Now just find x, and then tu. not sure how you get negative lengths.
August 29, 2016

algebra
m = g+150 2(m-190) = g Now just solve for m.
August 29, 2016

Math
just plug in x = -2 y(-2) = 2(-2)^2 + 8(-2) + 5 = 2*4 - 16 + 5 = 8-16+5 = -3 If y is a function of x, y(2) means evaluate y at x = -2, not multiply y by -2. Looks like you have some serious reviewing to do.
August 29, 2016

Math
recall that the vertex is at x = -b/2a In this case, that is at x = -8/4 = -2. y(-2) = -3 So, the vertex is at (-2,-3) You can also determine this by completing the square: y = 2x^2 + 8x + 5 = 2(x^2 + 4x + 4) - 3 = 2(x+2)^2 - 3 New recall that the vertex of y = a(x-h)^2 + k is...
August 29, 2016

Math
42
August 29, 2016

PHYSICS
see related questions below
August 29, 2016

Math
solve as if they were equations. The lines intersect at (-1/3, 4/3) The solution is the area to the right of x = -1/3, below the blue line and above the red line. see http://www.wolframalpha.com/input/?i=plot+y+%3D+2x%2B2,+y+%3D+-x%2B1
August 29, 2016

Math
Since all the numbers on the left are even, I can't see how to get an odd result.
August 29, 2016

Algebra2
If you want to reflect the whole graph across the x-axis, that would be -(x^2+5) = -x^2-5 Make a visit to wolframalpha.com and type in your functions. It will show the graph. Make a change a refresh, and you can see the new graph. You can do more than one at a time by ...
August 29, 2016

Algebra2
Let g(x) be the reflection of f(x)=x^2+5 What is the function rule for g(x)? I know the first part would be-x^2 but not sure if the 2nd part is a plus or minus.
August 29, 2016

Algebra2
thank you
August 29, 2016

Algebra2
Write an equation for the following transformation of y=x: a vertical stretch by a factor of 6. A. y=6x B.y=x/6 C.y=x+6 D.y=x-6 my answer is a
August 29, 2016

Algebra2
yes, because the +y axis is up
August 29, 2016

Algebra2
Thank you so the +5 number would always be up and a -5 number would always be down?
August 29, 2016

Algebra2
stretch vertically by 5: -35x^2 shift up 5: -35x^2 + 5
August 29, 2016

Algebra2
What transformations change the graph of (f)x to the graph of g(x)? f(x) = -7x² ; g(x) = -35x²+5
August 29, 2016

Math
If you mean effort then you are right. Maybe some of that effort should go into spelling, typing, or proofreading...
August 29, 2016

math
75% is 3/4 so, 1/4 failed so, what is 1/4 of 36?
August 29, 2016

phisics
After t hours, the total distance is covered, so 7.8t+7.6t = 6.0+4.2 t = 0.662 hr So, A's final position after that long is -6 + 7.8 * 0.662 = -0.836 km or, 836 meters west of the pole.
August 29, 2016

math
the perimeter is half a circle plus the diameter, so 3π+6 assuming the shaded shape is the semicircle. If not, I'm sure you can work it out.
August 29, 2016

physics
density = mass/volume, so (6×10^3 kg) / (4π/3 * (6.4×10^3 km)^3) If you do the division, you will see an unexpectedly small result You sure the mass of the earth is only 6 metric tons?
August 29, 2016

Maths
well, you know that 2x(3x-4) = 6x^2-8x (x-1)(x+3) = x^2+2x-3 now just subtract
August 29, 2016

Math
correct
August 29, 2016

Math
If I gave you $2 each hour, how long would it take for you to have $8? Same problem, but using positive numbers.
August 29, 2016

Math
differences: 10,10,10,10 looks like an AP to me.
August 29, 2016

physics
not sure what "four folded" means. If you mean the cross-section area is multiplied by 4, then the resistance is divided by 4. If the diameter is multiplied by 4, then the resistance is divided by 16 If the length is multiplied by 4, then also the resistance.
August 29, 2016

mathematics
AP/AB = 2/3 (AP+2)/AB = 3/4 (AP+2)/AP = 9/8 1 + 2/AP = 9/8 2/AP = 1/8 AP = 16 16/AB = 2/3 18/AB = 3/4 AB = 24
August 29, 2016

Math
If the two numbers are x and y, then y = 3x-1 2x+y = y+18 Now just solve for x and y
August 29, 2016

math
assuming you meant "tens digit" then you might have 123 124 ... 689 789
August 29, 2016

math
2/3 + (1/2)(1/3) = 5/6 So, 1/6 of the original number is 6
August 29, 2016

radical equation please help!!!
If you're trying to solve the equation, √(1+x) - √(1-x) = √(1-x-√(1+x)) (√(1+x) - √(1-x)) = √(1-x-√(1+x))^2 (1+x) - 2√(1-x^2) + (1-x) = 1-x-√(1+x) 2 - 2√(1-x^2) = 1-x-√(1+x) 1+x = 2√(1-x^2)-&#...
August 29, 2016

math help please?!
minors and cofactors are simple; just follow the rules. I'll do the ones for [1;1] minor: remove row 1 and column 1: [-2 6] [3 -6] cofactor: add the index of the row and column, and use that as an exponent of -1, then multiply the minor by that: (-1)^(1+1) = (-1)^2 = 1 so...
August 29, 2016

Math
oops. du = -5cos^4x sinx dx things are a bit more complicated than I showed here, since you wind up with a sin^2(x), which has to be converted into (1-cos^2 x) and you go around again.
August 29, 2016

Math
∫(cos^3 x)^2 ⁡dx = ∫cos^6 x ⁡dx Now, just as cos(6x) can be expanded into a polynomial in cos(x), cos^6(x) can be expanded into a sum of cosines of multiple angles: = ∫(1/32)(15cos(2x)+8cos(4x)+cos(6x)+10) dx = 1/32 (15/2 sin(2x) + 2sin(4x) + 1/6 ...
August 29, 2016

Math
Let x,y,z be the amounts of the three, in the order named. Then x+y+z = 24 x+z = 2y y+z = x Now solve for x. Hint: it is not 21
August 29, 2016

Physics
a = 50kph/8s = 25/4 km/hr/s = 1.736 m/s^2 Vo = 40 km/hr = 11.11 m/s, so s = Vo*t + a/2 t^2 now just plug in the values for Vo,a,t
August 29, 2016

applied maths
Draw a diagram of the box with the sides unfolded and lying flat. Now draw a straight line from spider to fly, and the distance x is x^2 = (1/2)^2 + (3/2)^2
August 29, 2016

Calculus
see related questions below
August 29, 2016

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
6!
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

math
9
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

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