Monday

June 27, 2016
Total # Posts: 41,441

**Nutz**

–0.5(4 + x) = –1.3 -2.0 - 0.5x = -1.3 -0.5x = 0.7 ...
*May 10, 2016*

**math**

man - have you ever seen the graphs? google is your friend, as is your textbook. both are conic sections, but a parabola has eccentricity = 1 an ellipse has eccentricity < 1
*May 10, 2016*

**MATH HELP PLEASE**

#1 nope. you missed a minus sign #2 could be right, if there was supposed to be a +5 in there #3 nope #4 nope #5 nope. you added, but you should have subtracted. If I ask how much bigger 6 is than 2, you don't add 6+2. #6 nope. you add exponents when multiplying powers. ...
*May 10, 2016*

**Algebra**

collect like terms and you get 8x^2+8x-3
*May 10, 2016*

**Math Please Help**

#1 ok #2 nope. You picked the chance of getting a vowel, but that's not what they asked. #3 ok #4 ok #5 ok
*May 10, 2016*

**Analytic Geometry**

you know it has a double root at x=0 so, the graph is tangent to the x-axis at (0,0) The graph crosses the x-axis at x=4 y is positive for large negative values of x, so the graph comes down from the left, touches (0,0), goes back up and crosses at (4,0) on its way down to the...
*May 10, 2016*

**calculus**

Hmmm. I misspoke. The average value is ∫[0,2] V(t) dt -------------------- 2-0 = 0.3010
*May 10, 2016*

**calculus**

That would just be (V(2)-V(0))/(2-0) = 0.6554/2 = 0.3277
*May 10, 2016*

**Linear Algebra - urgent!**

google is your friend. You could start here: http://math.stackexchange.com/questions/986859/why-is-deta-lambda-i-lambda-cn-when-a-cin-0
*May 10, 2016*

**Algebra 2**

not quite sure what you mean by t time is on 120 sec From what you said, it appears that h = at^2 + 35000 But, from the two data given, it looks like h(120) = 35000
*May 10, 2016*

**Math**

well, jeez - look at the 7 row. How many 8's are there?
*May 10, 2016*

**Maths grade 12**

of course , if siny = 0, then we have cosy = 1 or -1. You can try those for other solutions.
*May 10, 2016*

**Math (please help)**

the box is 8" long, so the paper has to be long enough to wrap around the ends. I'd say (D)
*May 10, 2016*

**math**

center is at (-6,5) so (x+6)^2/a^2 + (y-5)^2/b^2 = 1 The semi-major axis is vertical,and of length 13. c^2 = a^2-b^2 165 = 169-4, so b=2 (x+6)^2/4 + (y-5)^2/169 = 1 see http://www.wolframalpha.com/input/?i=ellipse+%28x%2B6%29^2%2F4+%2B+%28y-5%29^2%2F169+%3D+1
*May 10, 2016*

**maths**

recall that the product of the roots will be f/1 If f is prime, then the only possible rational roots will be ±1, ±f Since f and -f cannot both be roots (why?) there can be at most 3 rational roots. Furthermore, since f is positive (why?), -1 cannot be a root, ...
*May 10, 2016*

**calculus sir damon help me or steve**

recall your half-angle formulas for hyperbolic functions: sinh(x/2) = √((coshx-1)/2) so, √(coshx-1) = √2sinh(x/2) dx/√(coshx-1) = 1/√2 csch(x/2) dx now just use your standard form for integrating csch(u)
*May 10, 2016*

**math**

k = .6l l = .6m m-140 = l now just find k+l+m
*May 10, 2016*

**math**

a+b=108 3a/4 + (2/5)(b+a/4) = (3/5)(b+a/4) now just solve for b.
*May 10, 2016*

**geometry and trig**

If the cylinders are similar, then the ratio of volumes is (10/4)^3 as much, or 15.625 lbs = 250 oz how did you get 137pi? I suspect something is left unsaid here, as none of the choices seems right.
*May 10, 2016*

**algebra 1**

well, he is 1.75 std above the mean, or 28 + 1.75 * 8
*May 10, 2016*

**Mayh**

1/2 of 1/2 = 1/4
*May 10, 2016*

**math: probability**

wrong.
*May 10, 2016*

**math: probability**

correct, if you replace the first card before drawing the second.
*May 9, 2016*

**Algebra**

ignoring the mysterious comma, 3fg(f^2+5f-4) = 3f^3g + 15f^2g - 12fg
*May 9, 2016*

**math**

sounds like a rectangle to me.
*May 9, 2016*

**Science**

the same
*May 9, 2016*

**calculus**

(lnx)/(x) x^(lnx-1) = x^(lnx)/x
*May 9, 2016*

**calculus**

Is the lnx/x suppose to be (lnx)/(x) or ln(x/x)?
*May 9, 2016*

**calculus**

I don't understand how you went from y' = lnx x^(lnx -1) + lnx x^lnx (1/x) to lnx/x x^lnx + lnx/x x^lnx. Where did the -1 go? May you please explain?
*May 9, 2016*

**calculus**

recall that d/dx x^n = n x^(n-1) d/dx a^x = lna a^x so, if y = u^v, y' = v u^(v-1) u' + lnu u^v v' Here you have u = x v = lnx So, y = x^lnx y' = lnx x^(lnx -1) + lnx x^lnx (1/x) = lnx/x x^lnx + lnx/x x^lnx = 2lnx/x x^lnx or, do it like this y = x^lnx lny = lnx...
*May 9, 2016*

**calculus**

Find dy/dx. y = x^ln x, x > 0
*May 9, 2016*

**Math**

well, geez - did you plug in the values? y(0) = 5, so it will end in +5 1^2 = 1, so y = -x^2 + 5 so, yes, B is the answer.
*May 9, 2016*

**Algebra**

y = kxz 4 = k*4*1 k = 1 y = xz
*May 9, 2016*

**Algebra**

If the point is x miles from NYC, then since time = distance/speed, (3458-x)/(850+50) = x/(850-50)
*May 9, 2016*

**math**

Assuming you actually replace the 1st ball before drawing the 2nd, then the chance of drawing a green ball in at least one of the draws is the complement of drawing no green ball either time. The chance of no green ball twice in a row is 50/70 * 50/70 = 35/49 So, the chance of...
*May 9, 2016*

**Differentiation**

again?
*May 9, 2016*

**maths**

2(70 + 80+20) - 2(70+80) = 2(20) = 40 m or, 20m on each long side...
*May 9, 2016*

**Differentiation**

A = 3t^2 + 7 dA/dt = 6t now plug in t=5
*May 9, 2016*

**Math**

q = d+8 n = d-5
*May 9, 2016*

**Algebra**

Since time = distance/speed, 66/(r+7) = 24/r
*May 9, 2016*

**math**

1 + 6/16 = 1 + 3/8 = 1 3/8 can't see how that would have caused you any trouble...
*May 9, 2016*

**physics**

mv1 = <0,-144> mv2 = <-270/√2, 270/√2> add the vectors and then change back to direction and magnitude.
*May 9, 2016*

**functions**

A little division shows that 6x^3-ax^2+bx+c / (x+4) has a remainder of -16a-4b+c-384 6x^3-ax^2+bx+c/(x^2-4) has a remainder of (b+24)x+c-4a So, -16a-4b+c-384 = -220 b+24 = 23 c-4a = -26 solve those and you get f(x) = 6x^3 + 31/2 x^2 - x - 88 You can verify the remainders for ...
*May 9, 2016*

**MATHEMATICS**

geez, impatient much?
*May 9, 2016*

**MATH**

Draw a diagram. The distance x between the tree and pole can be found using 10.65/x = tan60° Then the remaining height y of the top of the tree and the top of the pole is found by y/x = tan46°
*May 9, 2016*

**math**

set it up in the usual way x^2-x+2 = 0 b^2-4ac = 1-8 = -7 so, what does a negative discriminant tell you?
*May 9, 2016*

**Geometry**

could be, depending on where the docks are. The docks could be anywhere from 0 to 40 yards apart.
*May 9, 2016*

**algebra**

good as far as you went, but 10/√27 10/(3√3)
*May 9, 2016*

**math**

sinA = 2 sinA/2 cos A/2 similarly for B and C Now add them up.
*May 9, 2016*

**math,science**

a = -22m/s / 13s = -22/13 m/s^2
*May 9, 2016*

**geometry**

you can easily see that the region is a rectangle. Rotate a rectangle around one of its sides and you get a cylinder. Then it's easy. See my work at http://www.jiskha.com/display.cgi?id=1462581546
*May 9, 2016*

**math**

This may help: http://mathforlove.com/2012/02/midpoints-of-a-quadrilateral-form-a-parallelogram/
*May 9, 2016*

**math**

the interest is the same for each year: 13000 * 0.08 clearly you need to review why the "normal" method works as it does.
*May 9, 2016*

**Algebra II**

well, π radians = 180°
*May 9, 2016*

**Algebra II**

use the law of sines
*May 9, 2016*

**geometry**

If they have the same base area, then the volumes are in the ratio of the heights, cubed. That is 250/2 = (H/h)^3
*May 9, 2016*

**Algebra II**

did you draw a diagram? If so, you can see that the distance x is found using the law of cosines: x^2 = 3.6^2 + 2.3^2 - 2*3.6*2.3*cos66˚
*May 9, 2016*

**math**

There are 20 greens in 70 gumballs The chance of drawing zero green ones is 50/70 * 49/69
*May 9, 2016*

**math**

the two terms are 9d apart. So, d = -2 Now you have d, and can easily find a, so S15 = 15/2 (2a + 14d)
*May 9, 2016*

**math**

huh?
*May 9, 2016*

**Trigonometry**

the height in feet can be found using h/5280 = tan6°
*May 8, 2016*

**Geometry**

V = 18*w*12 where the width is w.
*May 8, 2016*

**math: pre-calculus**

by definition, e^(ln x) = x ln(e^x) = x ln and e^ are inverse functions, just like x^2 and √x Assuming no typos, I see ln(e^3y)+ln(ey)-ln(e^4) = ln(e^3y * ey / e^4) = ln(y^2) = 2ln(y)
*May 8, 2016*

**math: pre-calculus**

you want p = a e^(kt) clearly p(0) = 53 p = 53 e^(kt) p(3) = 90, so 53 e^(3k) = 90 e^(3k) = 90/53 3k = ln(90/53) k = ln(90/53)/3 = 0.1765 so, we have p(t) = 53 e^(.1765t) Now you try the others, lest you be accused of homework dumping...
*May 8, 2016*

**geometry (please help)**

The area of the triangular base is (1/2)(9)(10) = 45 There are two of those, for a total of 90 There are three rectangular faces of area 9*10+9*9+9*13.5, for a total of 292.5 Total area is thus 90+292.5 = 382.5 in^2
*May 8, 2016*

**math: pre-calculus**

note that this is just log(x) shifted left 3 and down 8. So, now you can relate its properties to those of h(x)
*May 8, 2016*

**math**

just plug in the data and solve for w. Then you can get the length. w(3w-2) = 65 Of course, it also helps to know that 5*13 = 65 ... just sayin'
*May 8, 2016*

**algerbra**

since distance/speed = time, (1600/400) + (1600/320) = ?
*May 8, 2016*

**Math Algebra**

since distance/speed = time, 200/(x+3) = 200/(x-3) - 1
*May 8, 2016*

**math**

290-50 = 240 240/60 = 4 so, in 4 more hours
*May 8, 2016*

**Calculus**

V(0) = 500,000 V(5) = 405,000 (V(5)-V(0))/(5-0) = -19,000 ft^3/min
*May 8, 2016*

**math , steve or damon pls**

right on both of them.
*May 8, 2016*

**math**

pi, not pie! 2pi(r^2+rh) = 2pi(25+75) = 200pi Now just multiply that are by the cost, which is .0450/cm^2
*May 8, 2016*

**calculus**

let u = 2x you know lim sin(u)/u, right?
*May 8, 2016*

**damonnnn math help**

since multiplication is commutative, 6t^3 * 6t^3 = 6*6 * t^3*t^3 = 36t^6 t^3*t^3 = t*t*t * t*t*t = t^6, not t^9 add exponents when multiplying powers
*May 8, 2016*

**Geometric series**

a = -1 r = 3 Sn = (-1)(3^n-1)/(3-1) = (1-3^n)/2 = -3280 1-3^n = -6560 3^n = 6561 n = 8
*May 8, 2016*

**calculus**

what, you forgot your Algebra I? (x+1/x)^2 = x^2 + 2 + 1/x^2 Surely you can handle each of those terms...
*May 8, 2016*

**math**

figure the volume in ft^3, then multiply by how many gal/ft^3. That will give you how many gallons will fit. I have no idea how many gallons are actually in the tank...
*May 8, 2016*

**calculas**

let the distance from 3rd base be x. Then the distance z from home is z^2 = 90^2 + x^2 so, to find dz/dt, 2z dz/dt = 2x dx/dt So, find z when x=20, then plug in dx/dt and x.
*May 8, 2016*

**Maths - eh?**

If B is a point, how can a line be perpendicular to it?
*May 8, 2016*

**mathematics-permutation and combination**

The two boys are separated by 10 others on each side, right? Now you can easily figure the solution.
*May 8, 2016*

**math**

Just draw a diagram. All those right angles help a lot. XZ/2800 = tan(90-63)° 2800/XP = cos(90-25)°
*May 8, 2016*

**math**

x/180 = cot 27°
*May 8, 2016*

**Trigonometry and Right Triangles!**

the sides are in the ratio 1:√3:2 so if the hypotenuse is 16, then the sides are 8,8√3,16 and the perimeter is 24+8√3
*May 8, 2016*

**Math**

2x+5x = 4.27 x = .61 So, they have 1.22 and 3.05 lbs. Now you can decide how much has to be given so they have the same amount.
*May 8, 2016*

**math**

180/x = tan 27°
*May 8, 2016*

**math**

with A at (0,0) we just add the x- and y-displacements to get the final location: <4,0>+<0,-3>+<-3.06,-2.57> = <0.94,-5.57> Now you can find the distance and bearing.
*May 8, 2016*

**Maths**

x+y=120 0.9x + 1.2y = 120 80+40 = 120 72+48 = 120
*May 8, 2016*

**Math**

If the diamond is just a rotated square, then its diagonal is 3, so its area is 9/2. So, the rectangle has width 3 and area 27, so its height is 9.
*May 8, 2016*

**math**

Draw a diagram. It will be clear that using the law of cosines, the distance d is found using d^2 = 300^2 + 200^2 - 2*300*200 cos33°
*May 7, 2016*

**MATH**

1/14 (196x+17-10)= (14/20)(20x+12x) has no solution since (14/20)(20x+12x) = 14x + 42/5 and 1/14 (196x+17-10) = 14x + 1/2 and there is no value of x such that 14x+42/5 = 14x + 1/2
*May 7, 2016*

**MATH**

The equation 1/14 (196x+17-10)=______ (20x+12x) has no solution. The equation (4x+24/122)=_____ (x+16/122)
*May 7, 2016*

**MATH!**

not sure what question is answered by the 4, but you are correct in assuming that the equation is an identity.
*May 7, 2016*

**MATH!**

The equation 1/14 (196x+17-10)=______ (20x+12x) has no solution. The equation (4x+24/122)=_____ (x+16/122) Im sure the answer for the second one is 4, (4x+24/122) = 4 (x+6/122)
*May 7, 2016*

**math**

The answer is as follows: 9-3÷1/3+1 9-3*3/1+1 9-9+1 0+1 Answer = 1
*May 7, 2016*

**math**

other interpretations of 9 minus 3 divided by 1/3 plus 1 are (9-3)/(1/3) + 1 = 6*3+1 = 19 (9-3)/(1/3 + 1) = 6/(4/3) = 9/2 9 - 3/(1/3) + 1 = 9-9+1 = 1 9 - 3/(1/3 + 1) = 9 - 9/4 = 27/4 As you can see, using math symbols is a lot less ambiguous than just words, and grouping ...
*May 7, 2016*

**math**

you have correctly factored the left side. What has that to do with the right side? Or is that 16/22 a typo?
*May 7, 2016*

**math**

The equation 1/14 (196x+17-10)=______ (20x+12x) has no solution. The equation (4x+24/122)=_____ (x+16/122) Im sure the answer for the second one is 4, (4x+24/122) = 4 (x+6/122)
*May 7, 2016*

**math**

The equation 1/14 (196x+17-10)=______ (20x+12x) has no solution. The equation (4x+24/122)=_____ (x+16/122) Im sure the answer for the second one is 4, (4x+24/122) = 4 (x+16/122)
*May 7, 2016*

**math**

R = R1 + R2 = 10 + 15 = 25Ω
*May 7, 2016*