Wednesday
March 29, 2017

Post a New Question

Posts by Steve

Total # Posts: 49,729

Math (Semicircle)(Pre-calc)
a circle with center at (4,0) and radius 4 is (x-4)^2 + y^2 = 16 or, y = ?(16-(x-4)^2) The left semicircle has center at (-4,0) and radius 4, but lies below the x-axis, so So, f(x) = -?(16-(x+4)^2) for -4 <= x <= 0 ?(16-(x-4)^2) for 0 <= x <= 4
January 17, 2017

Math
If the meet after x hours, then 1.5 + 4.5x = 10x
January 17, 2017

Recursive Sequence and its Limit
A little work shows that the nth term a<n> = 3/(2^(n+1)-1) Now, do you want the limit of the terms, or the limit of the sums? a<?> = 0 S<?> = 3(sum 1/(2^(n+1)-1) I thought that would be relatively simple, but you can see below that it is not: http://www....
January 17, 2017

math
ok
January 17, 2017

Math
7P3 = 210
January 17, 2017

Math
the vertical distance moved is 12 sin25° = 5.07 ft Work = PE lost = 5.07 * 180 ft-lb
January 17, 2017

math
37A-A = 36A 36A/4A = 9 36A is the 10th term.
January 17, 2017

math
yes
January 17, 2017

Math
100 coffee a 50% solution ???
January 17, 2017

math
42 is the answer to The Ultimate Question of Life, the Universe, and Everything. So it is surely the answer to whatever puny question you have in mine.
January 17, 2017

math
42
January 17, 2017

Maths factorise
note that the fits two terms are 3p(x-y) and then use grouping.
January 17, 2017

Science
well, 1 mole fills 22.4L 28cm^3 = 0.028L So, you have .028/22.4 = 0.00125 moles (1/800 moles) Thus, if the mol wt is x grams, x/800 = 0.4 x = 320
January 17, 2017

Algebra
I assume the usual sloppiness with parentheses, and that your original equation was x/(x-2) + (x-1)/x + 1 = 0 If you found x=0 as one solutions, you need to exclude it. (x-1)/x is undefined when x=0 So, while it may appear that x=0 is a solution, it is not acceptable as a ...
January 17, 2017

Algebra 2
What you have is already in recursive form. Each An depends on the previous term. Now, if you want an explicit formula, An = 5*3^(n-1) + 2
January 17, 2017

Algebra 2
If you meant (2?(3x^5) - 2?y)^2 = 4(3x^5) - 8?(3x^5y) + 4y Not sure how that's any simpler, though...
January 17, 2017

Maths
Huh? If ABCD is a parallelogram. AB∥CD and has the same length.
January 17, 2017

Maths
recall that the area of a rhombus is 1/2 the product of its diagonals.
January 17, 2017

Mathematical Induction
you need to show that a<n+1> > a<n> (increasing) or a<n+1> < a<n> (decreasing) If you expand the expression from the recursion, you can clearly see that it is. Once you can show that each term is greater (or less) than the previous one, then you ...
January 17, 2017

riddle
Guys! This is easy! The answer is NEW MOON! The new moon is old and also 'new' at the same time!
January 17, 2017

math;);)
draw a side view. Draw a circle Mark a vertical diameter Draw a horizontal radius from the center O The radius has length 3 Draw another vertical line 1 unit away from the center. On that vertical line, mark its intersections with the horizontal radius (A) and the circle (B). ...
January 16, 2017

Calculus
Looks good to me.
January 16, 2017

calculus
f(x+3) = 2^(x+3) = 2^x * 2^3 = 8*2^x f(x-1) = 1/2 * 2^x PI, not PIE! G(0) = sin(2*0) = sin(0) = 0 similarly, just plug in the other values for x. These are some of your standard angles, whose trig functions you should know. They come up so often, it's better if you just ...
January 16, 2017

calculus
just look at the graph of sin(x). Clearly, it is defined everywhere, so its domain is all real numbers. sin(2x) gets to each x value twice as fast, but has exactly the same domain: all real numbers.
January 16, 2017

maths
make the two colors anything except black.
January 16, 2017

Math
tan(x) = 45/60 x = 36.87° As for the time of day, since you don't give any information on location, assume sunrise is at 6:00 am and sunset is at 6:00 pm. In that case, 180° of arc covers 12 hours. Use that to find how many hours after 6 am (or before 6 pm) it is.
January 16, 2017

9th grade algebra (sequences)
If you have an explicit formula, coming up with a particular term is easy. If not, you have to use the recursion several times. #1. try (-2)^(n-1) #2. You can use the explicit formula, but showing how to handle it as a general arithmetic sequence is also nice. Naturally, any ...
January 16, 2017

Math
what, you can't solve 4x+8 = 0 ??
January 16, 2017

Math
momentum is not measured in kg.
January 16, 2017

Algebra
(0.8-3.4)/(2007-1972) = -2.6/35 = -0.074 (hc/mile)/year if you want a % yearly rate, then that would be -0.77%/year
January 16, 2017

Math
Not quite sure what the "at 50m" means. Also, knowing the other stake is 65m from the end of the pond does no good. Now, if the two stakes are at the ends of the pond, and the given distances are as measured from the observation point, then the distance between the ...
January 16, 2017

Algebra
use the number of tickets, and the total income: s = 2a 10a+6s = 3300
January 16, 2017

math
because there was no bounce at first - just a drop. When it hits the ground for the 5th time, it has made a single 3-foot drop, and then 4 round-trip bounces.
January 16, 2017

maths trigonometry
you have the formulae. What do you get?
January 16, 2017

Math
yes, except 30*100 = 3000
January 16, 2017

math
n = k/(y^2-1) So, n(y^2-1) = k, a constant. You want n such that n(5^2-1) = 24(10^2-1) 24n = 24*99 n = 99
January 16, 2017

Math
Newton's method converges rapidly. If you don't have calculus, then there are other methods, such a bisection. f(x) = 6x + 12 + 2cosx Start off with the interval (-3,-1) and find f at the midpoint: -2 f(-2) = 6(-2)+12+2cos(-2) = -0.832 So, f=0 occurs in (-2,-1). f(-1.5...
January 16, 2017

Math
As I recall, (a) ?x P(x) means "there exists an x such that P)x) is true. So, in this case, that wold be P(-2) V P(-1) V P(0) V P(1) V P(2) Hmmm. Not sure what (c) ? ¬P(x) means. There exists "not P(x)"? Is that the same as ?x ¬P(x), that is there exist ...
January 16, 2017

Vector Calculus
Take a look at your previous post. See whether my solution makes any sense, and whether I interpreted things correctly.
January 16, 2017

Calculus
Just a note on #3 even though ?x^2 dx = x^3/3 ?cos^2(x) dx is NOT cos^3(x)/3 cos^2(x) = 1/2 (1+cos(2x)) since cos(2x) = 2cos^2(x) - 1 Thus, ?cos^2(x) dx = x/2 + 1/4 sin(2x)
January 16, 2017

Calculus
using discs of thickness dx, v = ?[0,2] ?r^2 dx where r=y=x^3 v = ?[0,2] ?(x^3)^2 dx = ?[0,2] ?x^6 dx = 128?/7 using shells of thickness dy, v = ?[0,8] 2?rh dy where r=y and h=2-x = 2-?y v = ?[0,8] 2?y(2-?y) dy = 128?/7
January 16, 2017

Calculus
#3 3. Use the washer method to find the volume of the solid that is generated by rotating the region in the first quadrant bounded above by y = cosx and on the right x = pi/2 about the line y=2 My work: pi((4(pi/2) - ((2-(cos(pi/2))^3)/3) My Answer: 11.36 v = ?[0,?/2] ?(R^2-r^...
January 16, 2017

Calculus
#2 This time, our discs are of thickness dy, so v = ?[0,2] ?r^2 dy where r=x = 3y/2 v = ??[0,2] (3y/2)^2 dy = 6? checking with shells, v = ?[0,3] 2?rh dx where r=x and h=2-y = 2 - 2x/3 v = ?[0,3] 2?x(2 - 2x/3) dx = 4?/3 ?[0,3] 3x-x^2 dx = 6? Your answer, 72?/12 = 6? is correct.
January 16, 2017

Calculus
#1 Zero? Really? That did not see strange to you? Too bad you didn't show your original integral. The graphs intersect at (-1,1) and (1,1). Since the area of a disc is ?r^2, the volume of a disc of thickness dx is ?r^2 dx. So, your integral should be v = ?[-1,1] ?(R^2-r^2...
January 16, 2017

Algebra
Nice work. I'd have changed things a bit here: Your system become: a * ( r ^ 2 - 1 ) = 12 a * r * ( r ^ 2 - 1 ) = 36 Divide the bottom by the top to get r = 36/12 = 3 a*8 = 12 a = 3/2
January 15, 2017

Algebra
ar^2 = a+12 ar^3 = ar+36
January 15, 2017

calculas
well, (a)(i) 4/(6-6.9) = 4/-.9 = -4.44 mPQ = (-4-(-4.444))/(7-6.9) = .444/.1 = 4.444 similarly for the other points (b) I expect you will guess m=4 (c) now you have a point and a slope, so the line is y+4 = 4(x-7)
January 15, 2017

vector calculus
The unit vectors are just the vectors perpendicular to the cylindrical surface. r^ points radially outward ?^ points tangent to the planar circle z^ points upward To convert to Cartesian vectors, r^ = cos? i + sin? j ?^ = -sin? i + cos? j z^ = z^ You have V = rrˆ + r^3 ...
January 15, 2017

vector calculus
Not sure what the R 3 means, but the transformation is just the usual polar-Cartesian we all know and love: x = r cos? y = r sin? z = z
January 15, 2017

Math
Hmmm. The statements are an exercise to see whether you can correctly evaluate and compare the expressions. Note that once a true condition has been found, the value of x changes, and the following statement works with a new value. There is no positive number such that x^2 = 5...
January 15, 2017

Math
Just work them. For example (a) is 3^2 = 5^3? No Some of the conditions will match, and then you can do the assignment. The last assignment done will be the new value for x.
January 15, 2017

Math
no idea. what was his cost? But, 2000/3600 = 5/9 So, he would have lost 4/9 of his previous sale value.
January 15, 2017

Pre Calc
This is a typical 3-circle Venn diagram. When you fill in the areas, the question should be easy. Start with the central 3-circle intersection. That is 4. ...
January 15, 2017

Math
10x+12=32
January 15, 2017

math
that's "lead" not led. The area of a disc of diameter d is pi/4 d^2. So, the area of the lead cross-section is pi/4 (2.4^2 - 2.2^2) = 0.723 cm^2 So, the mass of the lead is volume * density, or 0.723cm^2 * 350cm * 4g/cm^3 = 1012.2g
January 15, 2017

mathematics
hey! where's john? If you did the question and can find the value of x, then what do you want? As for me, I can find no value of x which works.
January 15, 2017

mathematics
and . . .
January 15, 2017

Algebra2
If you mean f(x) = 2x^2+x-3 then f(g) = 2g^2+g-3 = 2(x-1)^2+(x-1)-3 = 2x^2-3x-2
January 14, 2017

Algebra2
f(x)2x^(2)+x-3 g(x)=x-1 Perform the indicated operation, then find the domain (f*g)(x)
January 14, 2017

Education
Thank you very much
January 14, 2017

Education
The single best way to increase your income is to get an education. Why? 1- You automatically make more money if you are educated. 2- You automatically get promotions if you are educated. 3- You can obtain jobs that have higher starting salaries. 4- You will automatically ...
January 14, 2017

Calculas
x?¹-1 = 1/x - 1 = (1-x)/x So, your fraction is just (1-x)/x ---------- = -1/x x-1
January 14, 2017

Physisc
A 12 kg mass initially moving at 4 m/s is acted upon by a 120 N constant force. What is the final speed of the mass?
January 14, 2017

Applied calculus
the other dimension is (2000-2x)/2 = 1000-x I assume you know how to express the area of a rectangle.
January 14, 2017

Calculus
see related questions below.
January 14, 2017

Math
looks ok to me.
January 14, 2017

math
W = kL That is, W/L is constant. So, you want W such that W/14 = 105/7
January 14, 2017

math
what do you mean by A=50? A is an angle of ABC. Same for P P is a point. What do you mean by "find P"? If you want lengths of sides given the lengths of bisectors, then review the angle bisector theorem.
January 14, 2017

Arithmetic progression
"sum" not "some" Assuming you meant had she got 3 more in maths and 4 marks less in science I tried m+s = 28 (m+3)(s-4) = 180 If that's what you meant, then just solve for m and s.
January 14, 2017

Maths
the length+width must be 8. So, how many pairs of numbers add to 8? 1+7 2+6 ...
January 14, 2017

physics
The somewhat vague requirements give rise to the following equations of motion: a = 2/3 v + (2/3)t = 25 vt + (1/3)t^2 = B-A or 25t - 1/3 t^2 = B-A Without knowing how long it took to get from A to B (only knowing that it is less than 75/2 seconds - why?), that's all we can...
January 14, 2017

Algebra
-1375 + 450 = ?
January 13, 2017

Algebra
you should recognize those numbers as perfect squares.
January 13, 2017

Calculus
well, f'(Ø) = 2secØ tanØ + sec^2Ø = sec^2Ø(2tanØ cosØ + 1) = sec^2Ø(2sinØ+1) f'(Ø)=0 when sinØ = -1/2 Now, what else is a critical number?
January 13, 2017

Calculus
Think about what you know about the shape of |x| functions. They have a cusp, where the slope is discontinuous.
January 13, 2017

Precalc
when cos(pi/6 (t+2)) = -1 That is, where pi/6 (t+2) = pi
January 13, 2017

Algebra 1
try this: http://calc101.com/webMathematica/long-divide.jsp
January 13, 2017

Calculus
check your text or google to review what differentiable means.
January 13, 2017

Algebra
1 ok 2 is 7 < 3? 3 "<" means less
January 13, 2017

math
2x-4 = x+11
January 13, 2017

maths
well, there will be two days that occur 53 times. So, ...
January 13, 2017

dynamics of rigid bodies
I'll assume you meant s = 5t^2 + 1/3t^3 -1/50t^4 so, v = 10t + t^2 - 2/25 t^3 max v occurs when v'=0, so a = 10 + 2t - 6/25 t^2 So, find t when a=0, and then figure v at that value of t. max acceleration is when a'=0 a' = 2 - 12/25 t
January 13, 2017

math
15% of original, (.15*24000) or 15% off original ((1-.15)*24000) ??
January 12, 2017

Calculus
h = u/v h' = (u'v-uv')/v^2 Now just let u = 3x+2 v = x^2-5 Now each step is easy.
January 12, 2017

Riddle
well, you said her mom kept 6
January 12, 2017

pre-algebra
depends on what you mean by solve the question. Drawing a graph is one way to illustrate the relation between x and y. Another way is to fill in a table of matching values. Pick values for x and calculate the matching y values. Other questions might be to determine the axis ...
January 12, 2017

math
it is an odd function, so it is symmetric about (0,0)
January 12, 2017

Geometry
just use the distance formula.
January 12, 2017

Precalculus
well, every 2pi brings theta back to the same point, so ...
January 12, 2017

math unit 7 test
it should be clear that the inside of the arch cannot be covered by another arch.
January 12, 2017

math
ask google many many discussions
January 12, 2017

Math
5 ...
January 12, 2017

Graphing in the coordinate plane unit test
try google on some key topics...
January 12, 2017

algebra
try here. It shows all the steps. http://calc101.com/webMathematica/long-divide.jsp
January 12, 2017

Mathematical measurement
sure looks like 5:12 to me
January 12, 2017

Computing
n=1 s=1 for (i=1;i<=5;i++) { print s; n += 2; s += n }
January 12, 2017

Computing
depends on what information you want No idea what the "output of a triangle" is
January 12, 2017

C
add the numbers and divide by 10. If they are in an array called n, then sum=0 for (i=0 to 9) sum += n[i] avg = sum/10
January 12, 2017

math
4x-6 = x+15
January 12, 2017

Physical science
use the lengths as the legs of a right triangle. But, if the are not acting perpendicularly, you're out of luck.
January 12, 2017

  1. Pages:
  2. <<Prev
  3. 11
  4. 12
  5. 13
  6. 14
  7. 15
  8. 16
  9. 17
  10. 18
  11. 19
  12. 20
  13. 21
  14. 22
  15. 23
  16. 24
  17. 25
  18. Next>>

Post a New Question