Saturday
December 3, 2016

Posts by steve

Total # Posts: 46,781

math
I recall such rates in about 1964, but it was, of course, compound interest.
November 19, 2016

Pre-calculus
This one is easier if you work on the right side. (sin(x-y)/cos(x-y)) / (sin(x+y)/cos(x+y)) (sinxcosy-cosxsiny)/(cosxcosy+sinxsiny) ------------------------------------- (sinxcosy+cosxsiny)/(cosxcosy-sinxsiny) Expand those products, and you will be able to factor out some (sin...
November 19, 2016

Physics
none, except against air resistance. For a given force at takeoff, the mass affects the acceleration.
November 19, 2016

Math
Think about y=x^2 x can be either plus or minus and produce the same y value. Sp, as y grows on one side of the axis, it also grows on the other side. Plot a few points.
November 19, 2016

java program
you mean display the code? Surely the payroll system displays its own information.
November 19, 2016

Algebra
well, 3n^2+5n-100 = (3n+20)(n-5)
November 19, 2016

maths
AC = 1/2 AB PC = 1/2 AC = 1/4 AB
November 19, 2016

Math
81 = 3*27 so, the number is 4*27
November 19, 2016

math
if the scale factor is s, then P2/P1 = s A2/A1 = s^2
November 19, 2016

Maths
You can start here. Once you know the side length of the triangle, you can get its area. https://owlcation.com/stem/Inscribed-Circles-and-Equilateral-Triangles-7-Hard-Geometry-Problems-and-Solutions
November 19, 2016

math
If the %ages are based on the gross, then she saves (628-148.90-628(.045+.08))*.10 = $40.06 If they are based on after-tax income, then she saves (628-148.90)(1-(.045+.08)))*.10 = $41.92
November 18, 2016

Precalculus
D: all reals R: all reals > 0
November 18, 2016

chemistry
f" = -36sin(6x) f' = 6cos(6x)+c f'(0) = 6+c = -5, so c = -11 f' = 6cos(6x)-11 f = sin(6x)-11x+c f(0) = c = -3 f = sin(6x)-11x-3 f(?/3) = sin(2?)-11(?/3)-3 = -11?/3 - 3
November 18, 2016

Math
boy, you don't give much away, do you? The average value is ?[a,b] f(x) dx ------------------     b-a So, what didn't work? ?[-1,2] 4x^3-3x^2 dx = x^4-x^3 [-1,2] = (16-8)-(1+1) = 6 6/3 = 2 So, where is f(x)=2? 4x^3-3x^2=2 x ? 1.137
November 18, 2016

Math
see the related questions below. Just use your function instead.
November 18, 2016

English
#1 means that you are in sustained flight higher than the clouds #2 implies that in a while you will come back down, as in "The cow jumped over the moon." #3 Lots of explanations online. You might start here: http://www.grammarbank.com/impersonal-pronouns.html
November 18, 2016

Calc
http://www.jiskha.com/display.cgi?id=1479256552
November 18, 2016

Math help please
yes
November 18, 2016

Math help please
geez -- impatient much?
November 18, 2016

Math help please
TeX is not much good here, as you can see.
November 18, 2016

Math help please
a pizza place charges $5 per pizza, with a $7 delivery fee. How much does a delivery order for x pizzas cost?
November 18, 2016

math
try just posting a problem without copying all the surrounding text, eh? Don't make us figure out the question as well as the answer. Clean it up and post it again. Maybe just one question. Learn from its solution and try more on your own.
November 18, 2016

Math
If the length is x, then 2(x + 2x-8) = 104
November 18, 2016

Math
since y=2x-5, 4x-(2x-5) = 7 Now solve for x, and then you get y.
November 18, 2016

Maths
The yacht should take a bearing of the harbour, and then sail on that heading. Not sure what 065T means, but I assume it's 65° clockwise from True North. If so, then the heading back to the harbour is found via Label the diagram as follows: H = harbour P = point of ...
November 18, 2016

Physics
conserve momentum: 3500(45) + 1600(-25) = (3500+1600)v
November 18, 2016

Functions
so, what is your work? Show how you did it.
November 18, 2016

Functions
Oh come on. Just plug in their definitions: g(x) = f2(x)-f3(x) = (1/8(x+16)^2-98)-(2x+24) = 1/8 x^2 + 2x - 90 f1(x)=0 is stupid, as it contributes nothing.
November 18, 2016

Functions - huh?
Determine an equation for this function WHICH function?
November 18, 2016

Calculus
the chain rule says that d/dx(fg) = f'g + fg' not f'*g'
November 18, 2016

Calculus
clearly, y(0) = 4 y'(0) = 0 So, a parabola with vertex there will work: y = 2x^2+4 or how about a cosine function? y = 4cos(x)
November 18, 2016

math
In standard form, x^2/9 + y^2/4 = 1 a = 3 b = 2 c = ?5 You are correct that the foci are at (±?5,0) The directrices are at x = ±a^2/c = ±9/?5
November 18, 2016

math
Clearly the distance z between the ships can be found using z^2 = (Ax-Bx)^2 + (Ay-By)^2 = (-t+20)^2 + (-2t+10)^2 = 5t^2 - 80t + 500 2z dz/dt = 10t-80 dz/dt = 0 when t=8. So, just evaluate z at t=8.
November 18, 2016

Algebra
#1 clearly A grows by 0.6 for each new term. suppose A(n) = 0.6(n-1) But, when n=0, A(0) = 0.3 so just add that at the start. A(n) = 0.6(n-1) + 0.3 #2 A(n) starts at 47 and drops by 15, so start with A(n) = 47-15(n-1) The (n-1) stuff pops up because the first term (n=1) has ...
November 18, 2016

math
oops. That gives the untranslated parameterization. You want to shift things, so x = sec(t)/3 - 2 y = 4tan(t) + 4 so that 9(x+2)^2 - (y-4)^2/16 = 1
November 18, 2016

math
you know that sec^2(t)-tan^2(t) = 1 so, let x = sec(t)/3 y = 4tan(t)
November 18, 2016

Math
just compare cost/volume
November 18, 2016

Math
a = pi r^2 da = 2pi r dr now just plug in your numbers.
November 18, 2016

Calc
Graph the function. The area is just a couple of triangles.
November 18, 2016

Calculus
sin^2(x^2) * 2x
November 18, 2016

Mathematics
"there" not "their" if the road (or walkway) has width w, then the length is 45-2w
November 18, 2016

Calc
f(3) = 27 f(0) = 0 so, the slope of the secant line is 27/3 = 9 So, you need 3c^2 = 9 c = ?3
November 18, 2016

Algebra
four times a number is 4w so, ...
November 18, 2016

math
There are clearly no real solutions, but you can factor it into (x^2-x+1)(x^2+x+1)(x^4-x^2+1) = 0 because x^8+x^4+1 = x^8+2x^4+1 - x^4 = (x^4+1)^2 - (x^2)^2 a difference of two squares Now you can find the roots of those quadratics
November 18, 2016

math
42
November 18, 2016

math
and inept at following instructions, it appears...
November 18, 2016

Order MATH!
2/3 = 0.66 7/10 = 0.70 now things should be clear.
November 18, 2016

maths
the area is just 1/2 ab the area is just 1/2 bc sin?
November 18, 2016

maths
(a) ? is easy, since the angles sum to 180° Then use law of sines to find b,c (b) this is a right triangle. a^2 = b^2+c^2 then just use the trig functions to get the other two angles. (c) use the law of cosines to get any or all of the angles. Or, having one, you can use ...
November 18, 2016

maths
find the reference angle in QI. only sin x is positive in QII. For example, cos x = ?2/2 x = 45° Since cos x < 0 in QII, that is the only solution. Work the others in like wise.
November 18, 2016

Maths
just list the terms. 6 is the last to appear.
November 18, 2016

Maths
Think of a rectangle. The maximal area is achieved when it is a square. Similarly for a rectangular prism, the maximum volume is when it is a cube. so, in this case, the sum is just 3?2001
November 18, 2016

Geometry
#4 Remember the 3-4-5 right triangle. This is just double that. You got #1 right. How could you not be sure on #4?
November 18, 2016

Geometry
#1 ok #2 the sides are 26/?2 = 13?2 If the sides of a square are 1, the diagonal is not 2. #2 In such a triangle, the sides are 1,?3,2 Now multiply everything by 8. (c) is wrong.
November 18, 2016

math
and how did you arrive at that figure? Take a piece of graph paper and draw a 6x8 rectangle on it. You really think the diagonal is 48? Think of the Pythagorean Theorem here.
November 18, 2016

Math
she got 1/6 wrong. so, ...
November 18, 2016

Calc
I assume you mean x^(2/5) since f' = 2/5 x^(-3/5) it is undefined at x=0
November 17, 2016

Calculus
are they the same?
November 17, 2016

Calculus
a = ?(x/2?)^2 + (14-x)/6 * (14-x)/3 P = (12+x)(27-3x) - (4x)
November 17, 2016

calculus
11,33,55,77,99,121,319,517,539,...,979
November 17, 2016

Math
see related questions below
November 17, 2016

mathematics
no idea. Where is D?
November 17, 2016

Math algebra
(20+2w)(30+2w) = 936 w = 3
November 17, 2016

Algebra
you want x^2+y^2+6y+5 = x^2+y^2-2x-8 6y+5 = -2x-8 y = -(2x+13)/6 Now use that to find x: x^2 + (-(2x+13)/6)^2 - 2x - 8 = 0 40x^2 - 20x - 119 = 0 x = [5±9?15]/20 y = -3/20 (15±?15) http://www.wolframalpha.com/input/?i=solve+x%5E2%2By%5E2%2B6y%2B5%3D0,+x%5E2%2By%...
November 17, 2016

math
a = bh/2 so, 5b/2 = 15
November 17, 2016

Linear Programming - The Graphical Method
This web site is very useful: http://www.zweigmedia.com/RealWorld/LPGrapher/lpg.html
November 17, 2016

Math (equation of tangent line)
2xy-1=(x+y+1)^2 2y + 2xy' = 2(x+y+1)(1+y') 2y + 2xy' = 2(x+y+1) + 2(x+y+1)y' y' (2x - 2(x+y+1)) = 2x+2 y' = -(x+1)/(y+1) So, your derivative is ok. when y = -1, x = -1, so y' = 0/0 so, what happens near (-1,-1)? If y = -1+h, x = -1+h+?(2h) so, y'...
November 17, 2016

Pre-Calc
sin(kx) has period 2?/k tan(kx) has period ?/k so, crank it out.
November 17, 2016

ELITRICAL MATH! (LAST ONE FOR TODAY, HOPEFULLY!)
divide cost/quantity $1.49/3ft = $0.4967/ft and similarly for the other one. Then compare
November 17, 2016

Math
8^-2 = 1/8^2 = 1/64 4^-2 * 2^0 = 1/16 * 1 = 1/16 5^(2-1+3) = 5^4 Your typos make things hard to read
November 17, 2016

Math
yes.
November 17, 2016

Math
just substitute: y = x-2, so x^2 - x(x-2) + 3(x-2)^2 = 15 3x^2 - 10x - 3 = 0 solve for x, than y=x-2.
November 17, 2016

Math
6 * 1/3 = 2
November 17, 2016

Algebra
You have two circles: x^2 + (y+3)^2 = 6 (x - 9/2)^2 + y^2 = 105/4 Naturally, they intersect where x^2+y^2+6y+3 = x^2+y^2-9x-6 6y = -9x-9 y = -(3x+3)/2 Subbing that into one of the equations, x^2+(3x+3)^2/4-9x-6=0 13x^2 - 18x - 15 = 0 x = 1/13 (9±2?69) y = -3/13 (11&...
November 17, 2016

Math
well, g = f-7 so what do you think?
November 17, 2016

Math
The only reason I can think of is that a measurement is subject to error (and is really only a decimal approximation), whereas the PT results is exact.
November 17, 2016

Differential Calculus
I do not know what cos^y means. I'll just use cosy and you can fix it as needed. x^2 cosy - siny = 0 2x cosy - x^2 siny y' - cosy y' = 0 y' = (2x cosy)/(x^2 siny + cosy) so, at (0,?), y' = 0 Since the tangent is horontal, the normal is vertical, and the ...
November 17, 2016

maths
40 = 360/9 so, 1/9 of the whole area.
November 17, 2016

maths
35 min = 7/12 of an hour. That is, 7/12 of the circumference of a circle with radius 6 cm. so, ...
November 17, 2016

Algebra
correct
November 17, 2016

Math
add up the total points so far. He needs 4*59 so, how many points short is he?
November 17, 2016

Maths
Check with "Ed" below ...
November 17, 2016

Maths
h = 1 + 3t - 4.9t^2 You forgot about gravity
November 17, 2016

Maths
h - 4.9 * 1.5^2 = 0 v = -9.8t
November 17, 2016

Math
try here: http://davidmlane.com/hyperstat/z_table.html
November 17, 2016

Geometry
also, 19x-11 = 10x+7
November 17, 2016

maths
ok, now what?
November 17, 2016

math
by, not bye 29+16/9 = 30 7/9 I assume you meant (28+16)/9 = 45/9 = 5 Online, parentheses make a big difference!
November 17, 2016

math
Looks like a good unit to study, all right. Do you have any specific questions that are causing you difficulties? Do not expect someone here to provide you with all the answers...
November 17, 2016

Scale Math HELP!!!!!!!!!!
1.29 * 6.5 * (how many sides?)
November 17, 2016

Fizik
All your numbers are missing, but just find the net force and then use F = ma v = at s = 1/2 at^2
November 17, 2016

Tod
input your data here for the solution, as well as a graph of the region: http://www.zweigmedia.com/RealWorld/LPGrapher/lpg.html
November 17, 2016

Math grade 6, four operations
a+b+c = 75 a-28+19 = b+28-24 = c+24-19 or a+b+c = 75 a-9 = b+4 a-9 = c+5
November 17, 2016

math
the image is the same distance above the line y = -2 as it was below it to start. So, y -> -2+(-2-y) = -2+(y+4) = y+2 (-1,-3) -> (-1,-1)
November 17, 2016

math
14/16 = 7/8 = 35/40 1/5 = 8/40 now just add them up
November 17, 2016

Maths
500,000 + .05*1000,000 + .125*(1,200,000x-1,000,000) = 1,400,000 Too many zeros! Let's knock of 000,000 and we have (in millions) 0.5 + .05*1 + .125(1.2x-1) = 1.4 Better check my numbers. I get x = 6.5 ...
November 17, 2016

math
since the numerators are all the same, larger denominators means smaller numbers.
November 17, 2016

Math
ok
November 17, 2016

Integral Calculus
Looks to me like an = (-1)^(n-1) (n+1)!/4^(n-1)
November 17, 2016

math
5(a+4d) = 12(a+11d) 5a+20d = 12a+132d 7a = -112d a = -16d so, what is the 17th term?
November 17, 2016

  1. Pages:
  2. <<Prev
  3. 1
  4. 2
  5. 3
  6. 4
  7. 5
  8. 6
  9. 7
  10. 8
  11. 9
  12. 10
  13. 11
  14. 12
  15. 13
  16. 14
  17. 15
  18. Next>>