Thursday
December 8, 2016

Posts by STEVE

Total # Posts: 46,981

Math
F·dr = sinx dx + cosy dy + xz dz Now just crank it out, using the definitions of x,y,z: ?4t^3 sin(t^4) - 3t^2 cos(t^3) + (t^4)(t) dt = -cos(t^4) - sin(t^3) + 1/6 t^6 [0,1] = -1 + 1/6 = -5/6
November 2, 2016

Math
this is just like the others. W = ?F•dr see the other posts.
November 2, 2016

Geometry (Please check my work)
Nope. Reflecting across the line y = -5 means that the image is as far below the line as (-2,-1) is above it: 4 units. So, (-2,-1) -> (-2,-9) Same with the line x=1. 3 to the left, so 3 to the right. (-2,-9) -> (4,-9) Reflecting across the line y=k: (x,y) -> (x,k-(y-k...
November 2, 2016

math
a number divided by 3
November 2, 2016

Algebra 2
none
November 2, 2016

Math
500,000 * 1.04^3
November 2, 2016

Maths
If the number of sides is n, then we have 180(n-2)/n = 10(360/n)-84 n=15 So, the sum of its interior angles is 180(15-2) = 2340°
November 2, 2016

@Writeacher
Writeacher, you're all right! =)
November 2, 2016

math
well, did you look at the formula? If a line with slope m passes through (h,k), its equation is y-k = m(x-h) So plug in your numbers.
November 2, 2016

Maths
Those numbers make no sense, either as absolute quantities or as percentages.
November 2, 2016

Algebra
The others are 180-(5x-20) = 200-5x or 180-(70-4x) = 110+4x In either case, opposite angles are equal, so if you want the actual numeric measure, just set the two expressions equal, solve for x, and the evaluate the expressions.
November 2, 2016

Math
v(t) = 6t^2 + ? a(t) = 12t + ? The ? is because you did not specify the power of t for the "45" term Anyway, fill it out and use your numbers. scrub...
November 2, 2016

Math
so, why don't you show us what you did? If you meant n/-3 + 5 >= 4 just work it as usual: subtract 5 n/-3 >= -1 Now multiply by -3 and change direction n <= 3 The reason you change direction is just a shortcut for moving things around by addition and subtraction: ...
November 2, 2016

Mathematics
the slope is -2, so y-5 = -2(x-1) y = -2x+7 2x+y = 7 2x+y-7 = 0 x/(7/2) + y/7 = 1 take your pick
November 2, 2016

piedad elementary school
try dividing out the common factor: 100/300 = 1*100/3*100 = 1/3 * 100/100 = 1/3 and so on. You will find one of the fractions has no common factor to use.
November 2, 2016

maa central
#blue / #total = 5/10
November 2, 2016

Calc III
Using symmetry, you can just take 4 times the volume in the 1st octant: 4?[0,?/2]?[0,4cos?]?[0,?(16-r^2)] r dz dr d? = 4?[0,?/2]?[0,4cos?] r?(16-r^2) dr d? = -4/3?[0,?/2] (16-r^2)^(3/2) d? [0,4cos?] = -4/3?[0,?/2] (64sin^3?)-(64) d? = -256/3?[0,?/2] sin^3?-1 d? = 256/3 ?[0,?/2...
November 2, 2016

Math
I assume you want to simplify in some manner. 7(4log2-(log3+log5)) + 5(2log5-(3log2+log3)) + 3(4log3-(4log2+log5)) now combine like logs, and you wind up with log2 Or, you can combine the factors first: 7log16/15+5log25/24+3log81/80 log ((2^4/(3*5))^7 * (5^2/(2^3*3))^5 * (3^4...
November 2, 2016

math
recall the multipliers of Pascal's Triangle: 1 3 3 1 Now use those in the expansion.
November 2, 2016

Ad.func
Let x = the distance from the wall a = angle of elevation of the bottom of the picture b = angle subtended by the picture Then we have 1/x = tan(a) 4/x = tan(a+b) we want b = pi/6. So, (tana + tanb)/(1-tana*tanb) = 4/x Now just plug in 1/x for tan(a) and solve for x
November 1, 2016

9th grade algebra (factoring with quadratic)
#7: x^2 - 18x + 57 = 0 Looks like the quadratic formula is what you'll need: x = 9±?24 Or, you could complete the square, as was done in the following problems: x^2 - 18x + 57 = 0 x^2 - 18x + 81 = 24 (x-9)^2 = ±?24 x = 9±?24 The rest look good, except ...
November 1, 2016

Trigonometry
amplitude is (95-80)=15 center line is 80, so start with the assumption that the minimum occurs at midnight (0 hours): y = -15cos(kx)+80 The function has a period of 24 hours, so 2?/k = 24, making k=?/12 y = -15cos(?/12 x) + 80 Now we know that the max occurs at x=15, not x=12...
November 1, 2016

Math
First, be sure that f(0)=f(1). It does since f'(x) = 3x^2-4x+1 = (3x-1)(x-1) just find a value in the interval [0,1] where f'(x) = 0. Now it's just algebra. The calculus is done.
November 1, 2016

Math
It appears that g(x) is constant, so it does not matter what f is. Fix the typo. Then just substitute f(x) for x in the definition of g. (g?f)(x) = g(f(x)) That is, if g(x) = x+3, (g?f)(x) = g(f) = f+3 = 4x-5+3 = 4x-2
November 1, 2016

maths
well, there are 42 eggs in total. Now work out the rest, based on that.
November 1, 2016

algebra
the total round-trip distance is 2 * 4 2/3 = 9 1/3 so, ...
November 1, 2016

Business math
He gets 2 years of interest on the original 500, and 1 year on the extra x. So, we want 500(1 + .085/2)^(2*2) + x(1 + .085/2)^(2*1) = 1000
November 1, 2016

maths
clearly David had 75 oranges. The rest then can be easily found.
November 1, 2016

Math
If the larger radius is r, then we have ?r^2 = ?(r-3)^2 + 15? r^2 = r^2-6r+9 + 15 6r = 24 r = 4 check: 16? = ? + 15?
November 1, 2016

Math
no digit can be 10.
November 1, 2016

Chem
It's hard to understand why you ask such a general-knowledge question here, rather than just going first to google. This would be a good place to start, both for the information, and the explanations on why the above question is rather ill-formed. https://www.webelements....
November 1, 2016

English
while syntactically gerunds are equivalent to infinitives in these uses, in practice, I doubt you will find anyone using the constructions in 2 and 4. I have heard #6. I guess because the word preceding the gerund is an adjective rather than a noun. #7 and 8 are both common, ...
November 1, 2016

Science
the acceleration indicates how much the velocity changes each second. Hence, v = at (m/s) = (m/s^2)(s)
November 1, 2016

Math
26 * 5 = 130
November 1, 2016

Math
12 + 14 = 26 * 5 This method is way easier
November 1, 2016

hellllllpppp
23/63 = 36% So
November 1, 2016

hellllllpppp
Damon is an uneducated tutor
November 1, 2016

hellllllpppp
He is un educated
November 1, 2016

math
LCM(84,35,52) = 5460
November 1, 2016

MATH
14f + 6e - 51
November 1, 2016

MATH
14f - 30 - 15e
November 1, 2016

Physics
acceleration= changevelocity/time
November 1, 2016

Math
If I understand this correctly, then if the digits of m are a and b, we have m = 10a+b and so 100a+10n+b = 11(10a+b) 100n+10a+b = 21n But this comes out with negative solutions. Maybe you can fix my logic and take it where it's supposed to go.
November 1, 2016

Maths
to find an average, add up all the values and divide by how many there are. Do those values end in 1 (one) or l (el)?
November 1, 2016

Maths
1cm = 10mm, so 54mm = 5.4 cm. 1/10=5.4/x, where x is equal to 54 (10 x 5.4).
November 1, 2016

Pre-algebra
It's -18/1
November 1, 2016

PLEASE CHECK OPERATIONS WITH FRACTIONS
1. A 2. A 3. C 4. A 5. B 6. B 7. D 8. B 9. A
November 1, 2016

PLEASE CHECK OPERATIONS WITH FRACTIONS
6. B - Correct 7. C - Incorrect it actually = D, -1/8 8. C - Incorrect it actually = B, 21 8/9 9. B - Incorrect it actually = A, -15/28
November 1, 2016

PLEASE CHECK OPERATIONS WITH FRACTIONS
So basically it is 1. A 2. A 3. C 4. A 5. B
November 1, 2016

PLEASE CHECK OPERATIONS WITH FRACTIONS
1. A - Correct 2. A - Correct 3. D - Incorrect, It = 1 71/72 So it would = C - 2 4. A - Correct 5. C - Incorrect, It = 34 122/221 So it would = B - 35
November 1, 2016

PLEASE CHECK OPERATIONS WITH FRACTIONS
Ok
November 1, 2016

Maths (really hard)
see related questions below
November 1, 2016

Mathematics
the equation is based on the fact that the range of water's freezing point to its boiling point is 180°F and 100°C So, the F degrees are 5/9 as big as the C degrees. So, it takes more of them to cover the range. Moreover, the F scale sets water's freezing point...
November 1, 2016

Maths
C = (5,-5/2) AC^2 = (5-4)^2 + (-5/2+3)^2 = 1 + 1/4 = 5/4 CB^2 = (6-5)^2 + (-2+5/2)^2 = 1 + 1/4 = 5/4
November 1, 2016

math
well, they all three add to 180, so ...
November 1, 2016

Algebra
If I understand this correctly, then if the digits of m are a and b, we have m = 10a+b and so 100a+10n+b = 11(10a+b) 100n+10a+b = 21n But this comes out with negative solutions. Maybe you can fix my logic and take it where it's supposed to go.
November 1, 2016

help maths
just google the topic. You might start here: https://www.whitman.edu/mathematics/calculus_online/section09.06.html I'm sure your text has examples of finding the centroid. If you are unsure about the shape, just see http://www.wolframalpha.com/input/?i=y%5E2+%3D+x(1-x)%5E2
November 1, 2016

help maths
PI, not pie!!! The center of gravity is clearly on the x-axis, so we just need to find the x-coordinate. Recall that x-bar = (integral x*f(x) dx)/(integral f(x) dx)
November 1, 2016

Converse of the Pythagorean Theorem
it's a right triangle if the longest side qualifies as an hypotenuse: a^2+b^2=c^2 Since 7^2 < 5^2+6^2 the triangle is acute. Similarly, if the c^2 > a^2+b^2, the triangle is obtuse.
November 1, 2016

Calculus
rearranging things a bit, we have y^3 = 9x^2+x-5 3y^2 y' = 18x+1 y' = (18x+1)/(3y^2) at (-3,1) that means y' = -53/3 However, (-3,1) is not on the curve. Typo??
November 1, 2016

Trig
2sinx = 1 - 2cosx sinx+cosx = 1/2 Now, sin(x+Ï€/4) = sinx cosÏ€/4 + cosx sinÏ€/4 = 1/√2 (sinx+cosx) SO, what you have is just √2 sin(x+Ï€/4) = 1/2 sin(x+Ï€/4) = 1/√8 x+Ï...
November 1, 2016

Sats
depends entirely on the distribution.
November 1, 2016

pre-calc
5000*1.1^20 vs 5000*(e^.1)^20
November 1, 2016

pre calculus
if the side is x, then the other side is 4000/x. So, we have x^2 + (4000/x)^2 = (x+10)^2 x ≈ 91 check: the rectangle is about 91x44 The diagonal is 101 = 91+10
November 1, 2016

7TH GRADE mATH
1500 * .0425 * 4
November 1, 2016

calculus
Hmmm. I see that my characters for pi and sqrt have been mangled. They appeared correctly as I typed them, but on redisplay are junk. r = sqrt(5/pi), h=2
November 1, 2016

calculus
v = Ï€r^2 h = 10 so, h = 10/(Ï€r^2) The surface area is a = 2Ï€r(r+h) = 2Ï€r(r + 10/(Ï€r^2)) = 2Ï€r^2 + 20/r da/dr = 4Ï€ - 20/r^2 = (4Ï€r^2-20)/r^2 da/dr=0 when 4Ï€r^2=20, or r=â&#...
November 1, 2016

geometry
if you mean that the center is (4,-1) and (8,2) lies on the circle, then r^2 = (8-4)^2+(2+1)^2 = 25 so the circle is (x-4)^2 + (y+1)^2 = 25
October 31, 2016

brief calc
a = ∫[4,5] 6x dx = 27 or, since the area is just a trapezoid of height 1, a = (24+30)/2 = 27
October 31, 2016

Algebra
the angles add to 180, so since R=Q+20, Q=R-20 S=Q+115 = (R-20)+115 = R+95 Q+R+S=180 R-20 + R + R+95 = 180 ...
October 31, 2016

Algebra2
Given no choices, I'd just have to say those closest to the turning points...
October 31, 2016

Algebra2
Which points are the best approximation of the relative maximum and minimum of the function? f(x)=x^3+3x^2-9x-8
October 31, 2016

Algebra
2(x + 4x-33) = 104
October 31, 2016

Algebra
add 9, multiply by 5, divide by -2 and change direction
October 31, 2016

Algebra
well, just plug and chug: R(x+h)-R(x) ----------------      h
October 31, 2016

Algebra2
A quadratic equation can be written in vertex form or in standard form. Sometimes one form is more beneficial than the other. Identify which form would be more helpful if you needed to do each task listed below and explain why. a- factor the equation b- graph the parabola c-...
October 31, 2016

Algebra2
y = -x^2+12x-4 = -(x^2-12x)-4 = -(x^2-12x+36)-4+36 = -(x-6)^2 + 32
October 31, 2016

Algebra2
What is the vertex form of the equation? Show steps y=-x^2+12x-4
October 31, 2016

Algebra2
thank you
October 31, 2016

Algebra2
Complex numbers can be graphed on the xy coordinate plane. TRUE OR FALSE My answer is yes
October 31, 2016

Algebra
still can't figure out what you mean by pedro works in 3 days and juan in 4 days does that mean that Pedro works for 3 days, and then Juan works for 4 days? It appears that you are saying it takes Pedro 3 days, and it takes Juan 4 days. Then you ask how long it takes each ...
October 31, 2016

plz sir reiny sir steve sir damon help sor bob
just use the chain rule d/dx arccosh(u) = 1/√(u^2-1) du/dx so, if u = x/√3, that becomes 1/√(x^2/3 - 1) * 1/√3 = 1 / √(x^2-3) since you know that cosh^2(u) = 1+sinh^2(u) d/dx coshu = sinhu, you have y = arccosh(u) coshy = u sinhy y' = 1 y'...
October 31, 2016

math
600 * 1.04^6
October 31, 2016

maths
the slope of AB is -1/4 So, the slope of AC is 4 AB has length √68 = 2√17 So, AC has length √17 = √(1^2+4^2) That means that C = A+(1,4) = (2,9)
October 31, 2016

pre algebra PLZZZ help
what string? and certainly, estimation is often easier than detailed calculation.
October 31, 2016

Pre-Calc/ Trig
4cos^2(2θ-π) = 3 cos^2(2θ-π) = 3/4 since cos(a-b) = cosa cosb + sina sinb, cos(2θ-π) = -cos(2θ) cos^2(2θ) = 3/4 cos(2θ) = ±√3/2 now cos π/6 = √3/2 so, 2θ = π/6, 5π/6, 7π/6, 11π/6 &#...
October 31, 2016

math
facing east, of course.
October 30, 2016

MS.SUE PLEASE HELP!!!
(3/4)(z+8) 6(3x+y) -5(2a+5) in each case, just divide each term by the number you want to factor out.
October 30, 2016

Permutations
11*10*9 = 990 or 11!/(11-3)! = 11!/8!
October 30, 2016

Algebra II
just split up the real and imaginary parts, as usual! 19+42i-21yi+28y = (19+28y) + (42-21y)i
October 30, 2016

calculus
∫√(v^2 sin^2(2π/T t)) dt Looks to me like just ∫|v sin(2π/T t)| dt The absolute value throws in a wrinkle, but the integral is simple enough.
October 30, 2016

Calculus differentiable and continous identify
For continuous, ya got me. Only F looks like it fails. For differentiable, surely F fails, because it isn't even continuous. Also, (a),(b),(d) fail because of the cusps. I am assuming that d(0) is defined somewhere on the y-axis. (f) fails because the ends of the semi-...
October 30, 2016

Physics 11 steve or any physics teacher helpURGENT
The total momentum must be conserved. If the boy slides away to the left, the box must move to the right, since momentum is a vector quantity.
October 30, 2016

algebra 2
If x is the number of years, you need (1 + .038/2)^(2x) = 3000/2000
October 30, 2016

algebra
80 is 4 half-lives, so at t=0, it was 16 (2^4) times as great.
October 30, 2016

Algebra
after x years, the value is 14000 * 0.98^x
October 30, 2016

Calculus AB
#1 f' = (3x+2)e^x since e^x is always positive, just determine where 3x+2 is positive, etc. #2 remember the point-slope form of a line. a) y= x^2 + (e^x)/(x^2 +1) at the point x=3. y' = 2x + (x-1)^2/(x+1)^2 e^x y(3) = 9+e^3/10 y'(3) = 6+e^3/4 So, you want the line ...
October 30, 2016

Math
type in your functions here, and see whether you can see how to arrive at the solutions. http://www.wolframalpha.com/input/?i=%7C(x-3)%2F2%7C
October 30, 2016

math
not sure what you have against a simple minus sign, dividion symbols, etc. The rest of us just use simple ascii characters, such as + - / * < <= > >= all are correct except #8 c+6 < -20 c < -26
October 30, 2016

Pre-Calculus
there are a few standard angles whose exact values we know. By combining them we can get exact values for other angles.
October 30, 2016

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