Friday
October 24, 2014

Posts by Steve


Total # Posts: 26,058

Calculus-Math
clearly u(x) = 2x-4 f(u) = u^7 y = f(u) = u^7 = (2x-4)^7
August 8, 2014

algebra
Sure. Pick an easy multiple of 7: 7*40 = 280 Now, going down and up as far as you need, count by 7's: 280,273,266,259,252 280,287,...,497
August 8, 2014

Duh - Algebra, not Calculus
Could have saved myself some work if I'd kept that in mind!
August 8, 2014

Algebra - wow - go with Damon
Nice one, Damon. My calculations get kind of complicated. Your is much, much simpler. At least we agree on the maximum y/x = 5.82
August 8, 2014

Algebra
The line y=kx is tangent to the circle in two places. This will occur in two places, one with maximum slope, and one with minimum slope (y/x). As a function of x, y = 3±√(6-(x-3)^2) Clearly the maximum slope is achieved on the upper half-circle. kx = -(x-3)/(y-3...
August 8, 2014

Math (fibonacci
y = 1985+x 200 = x+y Eliminate y and we have 1985+x = 200-x 2x = -1785 x = -892.5 and the numbers are 1985, -892.5, 1092.5, 200
August 8, 2014

math challenge
2 hours is 7200 seconds. one day is 1440 minutes. so, ...
August 8, 2014

Algebra
6.0 <= pH <= 6.5
August 8, 2014

Algebra
10 <= c <= 12 The middle time is (10+12)/2 = 11 Each extreme is only 1 away from 11, so |c-11| <= 1
August 8, 2014

maths
8 hours means $32 The rest must be in tips, or at least $118
August 8, 2014

Algebra
the total points are now 68+78+90+91 = 327 To average 85 on 5 tests, you need 5*85 = 425 So, how many points short is that?
August 8, 2014

math
since c = 2πr, r = c/2π since a circle has a = πr^2, a = π(c/2π)^2 = c^2/4π the square has perimeter 4*4π = 16π so, the circle has area a = (16π)^2/4π = 64π
August 8, 2014

Maths
10 = 2p-4 p = 7
August 8, 2014

Math 221
take a read here: https://people.richland.edu/james/misc/acmeth.html
August 8, 2014

Algebra 2
Read up on hexagonal numbers. You can get started here: http://en.wikipedia.org/wiki/Hexagonal_number
August 7, 2014

Algebra 2
is there a common difference? is there a common ratio? How about showing some effort here?
August 7, 2014

Algebra 2
If the 3rd entry were 116, it'd be arithmetic, with d=113.5 But as it is, it's neither
August 7, 2014

Algebra 2
what's the problem? Just write them out: a_1 = 0 a_2 = 5a_1 + 7 = 5*0+7 = 7 a_3 = 5a_2 + 7 = 5*7+7 = 42 and so on
August 7, 2014

Algebra 2
a_1 = -5 a_2 = 2(-5)+7 = 3 and so on
August 7, 2014

Algebra 2
a_1 = 9 a_2 = 3*9 = 27 and so on
August 7, 2014

Math 221
first note that each term has a w in it, so w(9-w^2) Now recall that a^2-b^2 = (a-b)(a+b), so since 9-w^2 is the difference of two squares (3^2-w^2), we have w(3-w)(3+w)
August 7, 2014

Algebra 2
Since you have figured r, and a = 0.48, Tn = 0.48*2.13^(n-1) T12 = 0.48*2.13^11 = 1965.25 S12 = 0.48(1-2.13^12)/(1-2.13) = 3703.98
August 7, 2014

Algebra 2
Clearly, a_n = 5*4^(n-1) So, S_16 = 5(1-4^16)/(1-4) =
August 7, 2014

Algebra 2
Sure. It's all clearly explained. For the first one, a_1 = 112 a_2 = -9.5*112(1-112) = 118104 and so on. Similarly for the other example.
August 7, 2014

trig
review your trig function definitions. I think that 41/x = tan 65 However, as your language is almost incomprehensible, it's hard to be sure.
August 7, 2014

Physics
In the absence of other factors, both will hit the ground at the same time, because the force of gravity is all that's acting on them, making them fall at the same speed. The horizontal speed of the bullet has no effect on the pull of gravity. However, in real life, the ...
August 7, 2014

math
b/g = 9/8 b = g/2 + 15 So, to start with there were 27 boys and 24 girls
August 7, 2014

computers
I'd say it's an IP address, as discussed here: http://technet.microsoft.com/en-us/library/cc958048.aspx and also, no doubt, in your study materials...
August 7, 2014

math
we have two points: (3,26) and (7,18) You are correct that y = -2x+b So, plug in either point. For example, 26 = -2(3)+b 26 = -6+b b = 32 y = -2x+32
August 7, 2014

math
no idea what "b" represents. And with only one data point, we cannot determine anything else. What was the starting pressure? Or, how much pressure did it lose each day? Please make sure your posting accurately reflects the problem as presented, maybe with some ...
August 7, 2014

math
a cubic foot is 12^3 = 1728 cubic inches. So, the quart weighs 60/1728 * 60 = 2.08 pounds But then we knew that, since "a pint's a pound, the world around."
August 7, 2014

physics
Just convert the data to rectangular coordinates: 11 @ 88° = 0.0349,10.9933 6.8 @ 115V = -2.8738,6.1629 so, now you want (x,y) such that 0.0349+x = -2.8738 10.9933+y = 6.1629 Then convert that (x,y) back to polar avlues.
August 7, 2014

Math
2^3 = 8 5^-2 = 1/5^2 = 1/25 so, (a) = 8/25 You cannot simply disregard the negative sign of the exponent, nor willy-nilly move items from bottom to top. You have directly replaced 2^-2 with 2^3 and 1/a^4 with a^4. 2^-3 = 1/2^3 = 1/8 So, (b) = 1/(8a^4)
August 7, 2014

MATH(HELP)
I believe your previous post said that there were then 30 more guppies than in the beginning. That means that there were 120 to begin with, since adding 1/4 of 120 means adding 30. However, that leaves us nothing to do with the goldfish or angelfish. I suspect you have still ...
August 7, 2014

MATH - eh?
list the facts: g/a = 2/3 a = 2/3 f The shop keeper decided to replace 1/4 of the guppies with some angelfish. The number of angelfish she added was equal to the number of the guppies she replaced. well, duh. Both sentences say the same thing. The last sentence leaves us ...
August 7, 2014

math
well, you have the equation. How many weeks from the time she started saving, until Christmas? $25/week, babe. I assume you know how many days per week . . .
August 7, 2014

math
looking at the data, it appears she saved #25 each week. So, after x weeks, her saving y would be y = 25x You can work into that by noting that if y = mx+b when x=7, 175 = 7m+b when x=15, 375 = 15m+b so, 8m = 200 m = 25 Now you have y = 25x+b plugging either point shows that b...
August 7, 2014

math
Sounds like a good plan. Was there a question in there somewhere?
August 7, 2014

Geometry
consider how many reds and the total cards there are for each draw. You multiply the chances for each event, giving 26/52 * 25/51 * 24/50
August 7, 2014

Math
Looks like 12 to me, since 144 = 12*12
August 7, 2014

spelling mistakes
theree guest lectures come from CMC hospital to give the trainee and her fellowmates a common introduction above community developement.
August 7, 2014

Statistics
well, 3000 is 1 std above the mean. So, check your Z table for the area of the tail above Z=1. Or, play around at http://davidmlane.com/hyperstat/z_table.html
August 7, 2014

physics
The average velocity is zero, but the speed is not. The total distance covered is 2d. The total time taken is d/40 + d/60 = 5d/120 So, the average speed is 2d/(5d/120) = 48 km/hr
August 7, 2014

Math
5[5m-(m+8)]> -4(m-1) 25m - 5(m+8) > -4m + 4 25m - 5m - 40 > -4m + 4 24m > 44 m > 11/6
August 7, 2014

mathematics
2(l+b) = p l+b = p/2 l = p/2 - b
August 7, 2014

math - eh?
Regardless of x, 2+3 = 5 Better try proofreading
August 7, 2014

math
44-(4x+5)< 2(x+2)+x 44-4x-5 < 2x+4+x 39-4x < 3x+4 35 < 7x 5 < x
August 6, 2014

Calculus-Math
since x^n/x = x^(n-1), y = 2x^(7/2)/x = 2x^(5/2) y' = 2(5/2)x^(3/2) = 5x√x
August 6, 2014

statistics
If there are n questions, there are 2^n ways to select a set to answer. That assumes that refusing to answer any at all is also an option. Read up on power sets.
August 6, 2014

math test review
since w = 25r, we need to increase by 3r, making the result 28r, which is always divisible by 7, since 7 divides 28, regardless of r.
August 6, 2014

math corrections
In that case, the speed ratio is 250/300, so the teeth ratio will be 300/250 * 30 = 36
August 6, 2014

math corrections
#2 A pair of pants sells for $6 more than 75% of its price of the pants? The question makes no sense. #4 (A) 0.750 - 0.625 = 0.125 But that is the difference in the diameter. The wall thickness is the difference in radius: half that, or 0.0625 #14 (D) since AB = 40°, <...
August 6, 2014

math
what, no calculator handy?
August 6, 2014

math
we need 1.50x + 10[x/30] >= 450 x >= 246.3 check: 1.50*246 + 10*8 = 449 His next sale will push him over $450
August 6, 2014

Geometry
the pentagon consists of 5 triangles, each with altitude 6.5 and base 9.4 Now it's easy, right?
August 6, 2014

Geometry - !!
Love it!
August 6, 2014

Geometry
Hello ... I mean sin -π/6 That is, because 2 cos θ/2 sin θ/2 = sinθ
August 6, 2014

Geometry
Hello... 2cosθsinθ = sin2θ so, what's sin -π/3?
August 6, 2014

Math
reduced. Actually, there is a link to the parts of a subtraction problem. In words, we have minuend - subtrahend ---------------- difference That is, the minuend is diminished by the amount subtracted (the subtrahend), yielding the difference. *sigh* it seems folks have lost ...
August 6, 2014

statistical analysis
sort the values in order The median is the middle value - there are the same number of values above and below it. since there are an even number of values, there is no center value, so average the two center values.
August 6, 2014

college algebra
looks good to me.
August 5, 2014

Geometry
Draw a diagram. If half the chord has length x, you have a right triangle. 5^2+x^2 = (5√3)^2 x^2+25=75 x^2=50 x = 5√2 So, XY = 10√2
August 5, 2014

Geometry
one of the "standard" right triangles is 8-15-17.
August 5, 2014

math
g(x) = x^3 - 9x^2 + 2x + 48 Look for the easy roots first: 1,2,3. A little synthetic division quickly shows that g(x) = (x+2)(x-3)(x-8)
August 5, 2014

Math
Hint. If the dining room has side x, then one side of the kitchen must also be s, and the width is 14. So, just add up the areas: x^2 + 14x = 275
August 5, 2014

Math
you know that ax^2+bx+c has its vertex at x = -b/2a. Here, that means the vertex (maximum no. tickets) occurs at x = 11 days
August 5, 2014

math
since 18-3+6 = 21, I'd say the blank holds a 4, since 12/4 = 3 Do the others in like wise.
August 5, 2014

math
17-3x5+4/2 17-15+2 4
August 5, 2014

Algebra 2
I suspect a notational problem. Why the -4(6)n? Is there supposed to be an exponent, as in 2^3=8? Do you mean -4*6^(n-1) ? That is, the terms are -4,24,-144,... Anyway, just plug your numbers into the formula for the sum of a geometric sequence. Sn = a (1-r^n)/(1-r)
August 5, 2014

Mathematics literacy
I suggest you provide some details. Normally, simplifying ratios is nothing more complicated than reducing fractions.
August 5, 2014

math
You appear to be given two points, not the slope and one point.
August 5, 2014

advance algebra
your algebra may be advanced, but your posting skills could use some improvement. I see what appears to be two points. So, what's the point? Or, they may be two intervals, or two vectors.
August 5, 2014

Calculus-Math
well, clearly, since f = 9g+h f' = 9g'+h', so f'(8) = 9g'(8)+h'(8) = 9*5-3 = 42 Of course -- that's the answer to the Ultimate Question of Life, the Universe, and Everything! I suspect a typo, since g(8) and h(8) are not used, but maybe there are ...
August 5, 2014

math
Aside from the trivial 1 and 2, I can only find less than 1,000,000 is 40585 Though it seems likely that there could be others near multiples of 9!
August 5, 2014

Statistics
for women, 2 ft is 1.6 std below the mean for men, 2 ft is 3.33 std below the mean. So, look those up in your Z table to see the break points. Or, play around at http://davidmlane.com/hyperstat/z_table.html
August 5, 2014

math
income = rate * customers I see nothing about how many hours she works per customer, so I'll just assume she works one hour each. Actually, we will see that if she works the same constant number of hours for each customer, the number does not matter. If the billable hours ...
August 4, 2014

Gen 499
what a-(hic)-bout it?
August 4, 2014

Math
Start substituting: 1/3c = 6b^2, so c = 18b^2 Now, 3b=2a, so 18b^2 = 2(3b)^2 = 2(2a)^2 = 8a^2 I think you left out a +6 somewhere, since there are no such terms shown. Also, if a=3 and b=2, c=72, not 78, so it's a good sign something has been left out. So, if D is the ...
August 4, 2014

algebra - oops
or, use 15/60 = 1/4 if you want a clser approximation! ...
August 4, 2014

math
or, you can consider it like this. The boats are approaching each other at 9 mph. The lake is 3 miles wide, so it takes them 1/3 hour to cover all the distance.
August 4, 2014

Calculus III
Sounds good so far. You can check your answer at http://en.wikipedia.org/wiki/List_of_moments_of_inertia More detailed drawings are found at http://hyperphysics.phy-astr.gsu.edu/hbase/isph.html and the rationale of adjusting the moment after removing the inside sphere is ...
August 4, 2014

Geometry
The lateral area is just πrs. Don't include the area of the base. so, πrs = 5πs = 65π, so s = 13 So, the height is 12, making the volume v = πr^2 h = π*25*12 = 300π
August 4, 2014

math
I'd say just 10. That's all there are.
August 4, 2014

calc
Hmmm. Your answer looks good to me. Although, I'd simplify it to just 3/√3 = √3
August 4, 2014

Chemistry
Na/NaCl = 23/(23+35.5) = .393 or 39.3%
August 4, 2014

math
first, clear up the meaning of x=2=2sqrty If you mean x = 2+2√y, then since the curve intersects y=9 at (8,9) we have as usual, two ways to solve it. Using shells of thickness dx, v = ∫[0,8] 2πrh dx where r = x and h = 9-y = 9-(x/2 - 1)^2 v = 2π∫[0,...
August 4, 2014

math
1000(1+.06/2)^2t <= 800(1+.08/12)^12t t >= 10.8 years
August 4, 2014

Math
since sin(x) = cos(90-x) sin^2 0° + sin^2 90° = 1 sin^2 5° + sin^2 85° = 1 ... sin^2 45° + sin^2 45° = 1 Now, you have excluded sin^2 0, but since that's zero anyway. You have 9 pairs, plus a single 45, so the sum is 9.5
August 4, 2014

algebra
since the shadow:height ratio is the same, 25.2/8.4 = x/20.7
August 4, 2014

General knowledge
What is google, and what does google do?
August 4, 2014

Algebra
we know that sum 9/3^n is just a geometric series, which converges. 9/(n*3^n) has terms which are even smaller, so it also converges
August 3, 2014

physics
so, if we name the takeoff point as (0,0) we want the vertex of the parabola to be at (5,4.5) The parabola can thus be written as y = -0.18(x-5)^2 + 4.5 so, at x=0, y' = 1.8 That means the initial angle is θ=60.9° Now you should be able to work out the velocity ...
August 3, 2014

math
the slope is 1/9, so the point-slope form tells us that y-2 = 1/9 (x+3) now just put that into standard form
August 3, 2014

math
the line is horizontal, so the y-value does not change. What function stays at -8 for any value of x?
August 3, 2014

math
using discs, of thickness dx v = ∫[-1,1] πr^2 dx where r = y = 1-x^2 So, v = π∫[-1,1] (1-x^2)^2 dx = 16/15 π Using shells, of thickness dy, we have to account for the two branches of the parabola, so it's easier just to use symmetry and get v = 2...
August 3, 2014

Geometry
you could draw a semicircle, then draw a tangent line for the stem of the J. Note that the tangent to the circle is perpendicular to the radius.
August 3, 2014

geometry
(18+2w)(15+2w)-18*15 = 234 w=3 since the frame is 3" wide, you can now determine its dimensions.
August 3, 2014

math
not much to sketch. Linear functions are just straight lines. So, draw the line through those two points. Done. The only problem is, y is not a function of x. Why not?
August 3, 2014

Grammar
"I" is singular. So, you need a singular noun.
August 3, 2014

College math
5logT+2logW+logZ
August 2, 2014

Pages: <<Prev | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | Next>>

Search
Members