Post a New Question

Posts by STEVE

Total # Posts: 50,503

Math (Integrals) (Basic Integration)
that is correct. There is no du to work with. I mean, I did all the algebra for you, and explained the 2nd example to show why it worked there.

Math (Integrals) (Basic Integration)
Nope. Not that easy. x^4+1 = x^4+2x^2+1 - 2x^2 = (x^2+1)^2 - (?2 x)^2 = (x^2+?2 x+1)(x^2-?2 x+1) 1/(x^4+1) = 1/[(x^2+?2 x+1)(x^2-?2 x+1)] = 1/(2?2) ((x+?2)/(x^2+?2 x+1) - (x-?2)/(x^2-?2 x+1)) = 1/(2?2) ((2x+?2)/(x^2+?2 x+1) - x/(x^2+?2 x+1) - (2x-?2)/(x^2-?2 x+1) + x/(x^2-?2 x...

Math
that depends on a number of values not given here, as I'm sure you can tell. Better research the topic a bit more.

Math please help me
just multiply all the numbers from 1 to 4: 4! = 1*2*3*4 = 24 5! = 1*2*3*4*5 = 120 and so on

tangential velocity physics
google is your friend. Or, consider that the moon is roughly 250,000 miles from earth It takes about 28 days to orbit once. So, its linear speed is 2pi*250000mi/28days Find out the actual values, in meters and seconds, and that will give you its tangential speed.

Math (Integrals)
Just expand the polynomial and integrate all the terms: 4x^2-4x+1 dx

Math
well, 363 = µ - 2? what does the rule have to say about that?

Mathematics
since cosine has a period of 2pi, either A=X or |A-X| = k*2pi Since both A and X are less than pi/2, A=X

Maths
(s/2)^3 / s^3 = (s^3/8) / s^3 = 1/8

Math
there are 26 choices for each letter. So, multiply.

Math
500 - 8*45 = ?

algebra
looks good to me

math
a = 3 Since the GP has a common ratio (a+3d)/(a) = (a+12d)/(a+3d) (3+3d)/3 = (3+12d)/(3+3d) 1+d = (1+4d)/(1+d) d = 2 a+9d = 3+9*2 = 21

MAth
950000 * 0.90^5

Math - Calc
see whether this helps http://www.wolframalpha.com/input/?i=plot+y%3Dx%2B6,+y%3Dx%5E3,+2y%2Bx%3D0

calculus
I get S-S6 = 5.93*10^-6 < 1.0*10^-5

Algebra
I disagree. Why are you subtracting the last terms?

Math
timothy's coins were 10 more than pearly's. So, if the new amounts were t' and p', 10 more than pearly = 10+p' t' = 10+p'

Math
t = 5/8 p t + 1/4 p = 10 + 3/4 p now just solve for t

Calculus indefinite integrals
(a) u = x^2-7 (b) u = 1/5 x^(5/3) + 2

Pre calc
looks like you need to review your basic identities and double-angle formulas: cos^4x-sin^4x = (cos^2x-sin^2x)(cos^2x+sin^2x) = cos^2x-sin^2x = cos2x (B) is clearly not true, since sin^2x/(1+cos^2x) has no asymptotes

Calculus - Integrals
The curves intersect at (-1,2) and (-1,-2) So, using horizontal strips of width dy, the area is a = ?[-2,2] (3-y^2)-(y^2-5) dy Using vertical strips, we have to split the region in two at the intersections, and then symmetry helps: a = ?[-5,-1] 2?(x+5)dx + ?[-1,3] 2?(3-x)dx

Math
add 30 ft to each dimension (15 ft on each side) then do perimeter as usual

algebra
vertical shrink by 4 shift down 12

Algebra
y = (3x^2+8x-10)/(x^2+7x+12) = (3x^2+8x-10) / (x+3)(x+4) no holes, since y is never 0/0 vertical asymptotes where the denominator is zero: x = -3,-4 as x gets huge, y -> 3x^2/x^2 = 3 so that is the horizontal asumptote http://www.wolframalpha.com/input/?i=(3x%5E2%2B8x-10)+%...

Math
The average lies somewhere between the lowest and highest values. There is no way that all the children in a group can be above the average for that group. However, it's possible that all the kids in Lake Wobegone are above the national average, or above the average of ...

Math
Of course it's possible. If 18 students get 100%, they all score above the average, which is less than 100.

Math
6C2 = (6P2)/2! = 6*5/2 = 15

science
C looks good to me.

Math
The wording is very strange. Maybe you mean there are thirteen 2/3-cup servings in a bag. In that case there are [13*(2/3)]/(1/2) = 52/3 = 17 1/3 half-cup servings

Calc 1
since e^(ln?) = ?, sin(?) is the first time the curve intersects the x-axis. So, the volume, using discs of thickness dx is v = ?[0,ln?] ?r^2 dx where r=y=sin(e^x) v = ??[0,ln?] sin^2(e^x) dx Now, sin(e^x) is not integrable using elementary functions. I guess you'll have ...

Geometry
Draw a horizontal line through M to intersect BT at P. Since MP is parallel to AC, angles TMP and TNC are congruent, making right triangles TMP and TNC similar. So, PT/PM = NT/NC since M is the midpoint of AB, P is the midpoint of BN. Thus, NC=2MP PT/MP = NT/2MP 2PT = NT Since...

math
10P4 = 10*9*8*7 = ? not sure what the 4- means

math 105
so, what is the rule? You have the mean and the std....

physics
correct

physics
T^2 is proportional to L/g. The mass has no effect. So, if A^2 = L/g B^2 = 2L/g B^2/A^2 = 2 B/A = ?2 ? 1.4 answer C

physics
Since the period T = 2??(m/k) y = 0.1 sin(?(k/m) t) = 0.1 sin(5t) the speed v = 0.5 cos(5t) which has a maximum value of 0.5

Math
4 6/12 - 3 8/12 = 3 18/12 - 3 8/12 = 10/12 so, 10" left or, 54"-44" = 10"

Math help plz
the area needed is ?r^2 + 2?rh = ?r(2h+r) = 6?(24+6) = 180? = 565

Math
#14 wants volume, not area the others look good.

math
For #1 and 2, type in your function at wolframalpha.com or any of many other fine graphing web sites. -4 = 4-8 7 = -4+11 so, (x,y) -> (x-8,y+11)

Pre calc
because I studied the double-angle formulas, as you need to do!

Pre calc
In QI, you have sinx = 5/13 cosx = 12/13 tanx = 5/12 sin2x = 2sinx cosx = 2(5/13)(12/13) = 120/169 similarly using the other double-angle formulas.

Pre calc
If this isn't even math to you, you clearly haven't been paying attention during the discussion of the double-angle formulas ... (1-cos2x)/sin2x = (1-(2cos^2x-1))/(2sinx cosx) = (2-2cos^2x)/(2sinx cosx) = 2sin^2x/(2sinx cosx) = sinx/cosx = tanx sin4x/sinx = (2sin2x ...

Urgent math help!!
Huh? You are in trig, and cannot tell what the x- and y- coordinates are? The point (-3,4) is at x = -3 y = 4 since r^2=x^2+y^2, r=5. sin? = y/r = 4/5 You got the right answer; was it just a guess?

Urgent math help!!
Draw your triangle in standard position. It is clearly a 3-4-5 right triangle. sin? = y/r

Trig
well, csc^2x-1 = cot^2x cot*cos/cot^2 = cos/sin * cos * sin^2/cos^2 = sin

Math
she kept 3/8 * 25 = ? kg

Math
you have to keep writing an equation; you just dropped off the right side. In any case, remember from your Algebra I that you usually need to set stuff to zero to solve. Now, using the fact that sin^2x+cos^2x=1, 2cos^2x+sinx-1 = 0 2-2sin^2x + sinx-1 = 0 2sin^2x-sinx-1 = 0 (...

Trig
oops, sorry Reiny...

Trig
Remember your double-angle formulas. You have tan(2*30) = ?3 Reiny dropped the 2 in the numerator...

Trig
(1+tan^2x)/tan^2x = 1/tan^2x + 1 = cot^2x + 1 = csc^2x

laplace transformation:help damon or steve or rein
In case you don't have an online calculator handy, L{1} = 1/s L{e^t} = 1/(s-1) = F(s) L{t^2 e^t} = (-1)^2 F"(s) = 2/(s-1)^3 L{y} = f(s) L{y'} = sf(s)-f(0) = sf(s)-1 L{y"} = s^2f(s)-sf(0)-f'(0) = s^2f(s)-s+2 L{y'"} = s^3f(s)-s^2f(0)-sf'(0)-f&...

Bachelor of computer science
I'm sure you can do the I/O. The calculation is if hours <= 0   print "error - no hours entered" else if hours <= 40    pay = rate * hours else   pay = rate*40 + rate*1.5*(hours-40) endif

math
make up your mind -- BASIC or FORTRAN ? in any case, find the prime factors of each number, and select all those common to both. Their product is the HCF.

algebra
I don't see an inequality either. But, since the cost is not zero, you know that profit < earnings

MAth
If x is the middle integer, (x+4)/(x-4) = 2

Calc
yes. The f"' nonzero makes sure that it's not just a cup like x^4.

Calc
the slope has a minimum at x=c. f"(c)=0 means it's an inflection point. Think of the graph f(x) = x^3

Math
suppose k" = -5 on [-3,0]. You know that k'(-2) = -4. So, k'(0) would be -4+2(-5) = -14 Now, suppose that k" = -2 on [-3,0]. k' would be -4+2(-2) = -8 So, -14 <= k'(0) <= -8 remember that k" is just the slope of k'. k'(0) will lie ...

Math
you have ?y ? k'(-2)*?x You have k(-2), so use ?x=0.6 If the curve is concave down, it lies below the tangent line.

Math
6x10^-5 * 700 = (6*7)x10^(-5+2) = 42x10^-3 4x10^5 * 1.5x10^7 = (4*1.5)x10^(5+7) = 6x10^12 Now just divide as usual

math
just solve the system a(r^5-1)/(r-1) = 61 ar^4 = 81 Hint: 81 = 3^4

math
draw a diagram. Using similar triangles, h/(9+6) = 5/6

MATH
there are 20 students. So, the chance of getting the two freshmen is 2/20 * 1/19 = 1/190 This just selection without replacement.

Precalculus
the only constant I see is -1/5 I guess that make the power clear, eh?

proofread
I'll let bob handle the physics. You need to proofread your post this time -- get rid of the sloppy typos and finish the question.

science URGENT!!
hello. amplitude is wave height...

science URGENT!!
wave height is amplitude. and it still does not affect the frequency or the speed!

Science
F = ma, so a = -144/15 = -9.6 m/s^2 75 mi/hr = 33.53 m/s v = Vo + at = 33.53 - 9.6t v=0 at t=3.49 So, it will take 1.6 + 3.49 = 5.09 seconds to stop No deceleration occurs during the first 1.6 seconds, so the distance is s = 33.53*5.09 - 4.9*3.49^2 = 110.99 m

Science. HELP!!
not at all. The speed of light does not change because of the color. The speed of sound does not change because the pitch changes.

Math
The first step is to remove the parentheses. Then what do you have?

SCIENCE
The key to this is to come up with the equation of motion. If you review the relevant section, you will easily see that h(t) = 70+40t-4.9t^2 v(t) = 40-9.8t Now just apply your skills from Algebra I to find the vertex and find h(t)=70 and v(10)

Math1
just as the last one, 50=7*7+1

Math1
yep, it's a trinomial. If you want to factor it, recall that 15 = 2*7+1

math
without parentheses, exponents are done first. Remember PEMDAS? Parentheses, exponents, mult/div, add/sub So, -4^2 is evaluated as -(4^2) If you want +16, then that is (-4)^2

math
8×5-(6+12)÷6 = 37 as for simplifying, it doesn't get much simpler than 37 ...

Science, Physics
        sinx(cosx-sinx) ---------------------------------- sinx(cosx+sinx)(cosx-sinx)

Science, Physics
      sinx(cosx-sinx) ----------------------------- sinx(cosx+sinx)(cosx-sinx)

Science, Physics
(e2x)1/x < (x+ex+e2x)1/x < (2e2x)1/x e2 < (x+ex+e2x)1/x < 21/xe2 Now take the limits, and since 21/x-> 1, e2 < (x+ex+e2x)1/x < e2 so (x+ex+e2x)1/x = e2

Science, Physics
(e2x)1/x < (x+ex+e2x)1/x < (2e2x)1/x e2 < (x+ex+e2x)1/x < 21/xe2

Science, Physics
(e2x)1/x < (x+ex+e2x)1/x < (2e2x)1/x e(2 < (x+ex+e2x)1/x < 21/xe21/x

Science, Physics
(e2x)1/x < (x+ex+e2x)1/x < (2e2x)1/x

math
no idea. how much area does a gallon cover?

Math
start by expressing each factor in scientific notation: 1.31x10^5 3x10^-4 Now just multiply as usual.

math
the whole pipe is the sum of its parts, right?

Math
Since you have two values for y, just set them equal to each other: x^2+2x = 3x+20 x^2-x-20 = 0 (x-5)(x+4) = 0 and you're home free...

College Algebra
Once you get to 5=5 you are done. There are infinitely many solutions. If you put the two equations to the same format, they are y = 5x-5 y = 5x-5 They are the same line. Any solution to one of them is also a solution to the other.

Math
a+12d = 27 a+6d = 3(a+d) Now just solve for a and d.

Math
I agree

Maths
you need to learn to use parentheses online to make it clear what you want, since otherwise, multiplication gets done before addition. You meant (cot^2(x)(sec(x)-1))/(1+sin(x))=(sec^2(1-sin(x))/(1+sec(x)) Apply some of your elementary identities: cot^2(sec-1) = (sec-1)/tan^2...

Maths
recall that (a^3-b^3) = (a-b)(a^2+ab+b^2) sin^2+cos^2 = 1 and it all drops right out.

chemistry
for the same reason that any other endothermic reaction is so considered...

Calculus
there are lots of online graphers. You already know what the graph looks like. The critical points are where secx=0 or tanx = 0 The concavity up or down is provided by the sign of y"...

MAth
so, just plug in the numbers, and you should get 129

College Algebra
no, it is actually .05x + .10y + .25z = 7.80 Now solve 'em!

maths steve reiny bob reiny!!! Help
One side is the distance from (3,4) to 2x+y+3=0 The other side is the distance from (3,4) to x-2y-1=0 The area of the rectangle is thus |2*3+1*4+3)/?(2^2+1^2) * |1*3-2*4-1|/?(1^2+2^2) = 13

Calculus
more like dy/(1+y) = x dx ln(1+y) = x^2/2 1+y = c e^(x^2/2) y = c e^(x^2/2) - 1

Physics
ever hear of google? http://www.physicsclassroom.com/class/1DKin/Lesson-1/Distance-and-Displacement

Pre calc
so, why don't you show us how you got it? I get in QIII tan? = sin?/cos? = 5/12, so sin? = -5/13 cos? = -12/13 in QIV sin? = -1/?10 cos? = 3/?10 You don't say what you want to do with that, but sin(???) = (-5/13)(3/?10)-(-12/13)(-1/?10) = 21/(13?10)

  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>>

Post a New Question