Saturday

December 10, 2016
Total # Posts: 47,035

**Math**

f(x) = 55

*November 10, 2016*

**college maths**

P(1 + .065/4)^4 = 1600

*November 10, 2016*

**Math**

Or, just find the cube roots of your numbers. For example, ?60 = 3.91 so, it is between 3 and 4, since 3^3 = 27 4^3 = 64

*November 10, 2016*

**Math**

start listing the cubes: 1: 1 2: 8 3: 27 ... Then pick the two numbers from column 1 that correspond to the cubes near your targets in column 2.

*November 10, 2016*

**pre-calculus @Damon is right**

Sorry - I missed the -2 ; read x=2

*November 10, 2016*

**pre-calculus**

(A) y = 1/(x-2)(x-5) (B) y = (x+3)^2 / (x-2)(x-5) (C) y = 3(x+3)^2 / (x-2)(x-5)

*November 10, 2016*

**math**

T1 = 12 Tn = (-1)^n * |Tn-1| - 3

*November 10, 2016*

**Math**

If the side is x cm, then 4(x-2*4)^2 = 144 Or, since the height of the box is 4 cm, and 144/4 = 36, the final base of the box is 6x6 cm. That makes the original size 14x14

*November 10, 2016*

**math help**

google is your friend. Just look for "fractions math examples" and you will get lots of hits.

*November 10, 2016*

**pls help!!! -- typos galore!!**

#1 (a) unbalanced parentheses 9>4t<l) ?? both f and t a d l? Fix the typos and try again. Use * for multiplication online. And 7-+4 is probably better just as 7-4 (unless you meant something else) #2 google makes a good calculator. But even without it, the only numeric ...

*November 10, 2016*

**physics**

The induced emf in a coil is equal to the negative of the rate of change of magnetic flux ... So, if the flux increases, the emf decreases, but the absolute value increases.

*November 10, 2016*

**math**

Try this instead: I know how to spell, and I know grammar. Here is the sentence again: "Hi, I am of no help to you because I don't know the answer. Sorry, hope you pass the class." and by the way, sorry for having fun (_><_); it's not a privilege, it&#...

*November 10, 2016*

**@Anonymous**

What a waste of posting. Since you are no help here, maybe you can work on your spelling and grammar.

*November 10, 2016*

**Finite math**

Suppose the initial amount is x, the monthly rate is r=1.01, and the fee is f. Then the amount left at the end of each month is x*r-f (xr-f)*r-f = xr^2-fr-f (xr^2-fr-f)*r-f = xr^3-fr^2-fr-f The amount at the end of the nth month is thus xr^n - f(r^n-1)/(r-1) So, for your ...

*November 10, 2016*

**Calculus**

yes.

*November 10, 2016*

**English**

they are all adverbial phrases. They are all modifying the verb. I guess syntactically they could be adjectives working on the direct objects, but I think the sense is clearly that the enjoying and the visiting are what is in London and Chicago.

*November 10, 2016*

**physics 1**

This was something you had to post a question on? Surely your text discussed the units. then there's always google.

*November 10, 2016*

**Math algebra**

(88+92+97+96+x)/5 = 90 You had a hard time following the explicit instructions?

*November 10, 2016*

**Math**

10*180/12

*November 10, 2016*

**Math**

so, which pair of points lie on the line?

*November 10, 2016*

**statistics**

No idea. Add up all the weights and see.

*November 10, 2016*

**math**

3a - 4 < 5 add 4: 3a < 9 only one step left...

*November 10, 2016*

**physics**

think about it. A deceleration of 2 m/s^2 means that the velocity decreased by 2 m/s each second. So, here, the velocity changed by -25 m/s in 4 seconds. Look at the units. How do you get from m/s to m/s^2?

*November 10, 2016*

**Math**

m < 7

*November 10, 2016*

**math**

just write down the facts. If there are a,b,c,d of 5,10,20,50 notes, then b=5a b=4c b=10d 5a+10b+20c+50d = 8400 Now just plug and chug

*November 10, 2016*

**maths sir steve help~reiny**

since cos(z) = sin(?/2 - z) sin(?cosx)-cos(?sinx)=0 sin(?cosx) = cos(?sinx) sin(?cosx) = sin(?/2 - ?sinx) so, ? cosx = ?/2 - ?sinx ?(cosx+sinx) = ?/2 cosx+six = 1/2 You can probably take it from there, eh?

*November 10, 2016*

**math**

no idea. But I'll check yours.

*November 10, 2016*

**math**

no idea, but I'll be happy to check yours.

*November 10, 2016*

**Algebra2**

thank you

*November 10, 2016*

**Algebra2**

Wind farms are a source of renewable energy found around the world. The power P (in kilowatts) generated by a wind turbine varies directly as the cube of the wind speed v (in meters per second). If a turbine generates 500kW in a 10m/s wind, how much power does it generate in a...

*November 10, 2016*

**Math**

(3 * 1/4 mi) / (4.5min) * 60min/hr = 10 mi/hr

*November 9, 2016*

**CALCULUS**

well, you know the distance z at time t is z^2 = (130-30t)^2 + (20t)^2 = 1300t^2 - 7800t + 16900 so, at 4:00, z = 10?145 z dz/dt = 2600t - 7800 = 2600(t-3) Now plug in t=4

*November 9, 2016*

**Algebra- Word Problem**

each pet has at least two legs. No way can 40 pets have only 56 legs!

*November 9, 2016*

**Math**

Can't be sure, but I'd guess 7.2

*November 9, 2016*

**math - hmmm**

I think my answer to (c) is bogus. Still thinking on it.

*November 9, 2016*

**math**

(1) 1 (b) Must each bowl have at least one marble? (c) 12C2 * 6!

*November 9, 2016*

**The Tangent Function**

Or, method two simplifies a bit if you're not afraid of the cot(x) function: h cot25 - h cot30 = 40

*November 9, 2016*

**Math**

google "long division" for man examples of the method

*November 9, 2016*

**Algebra**

3/4 x + 4 <= 19

*November 9, 2016*

**math**

well, it would be stupid to have photos bigger than the album, eh?

*November 9, 2016*

**Natural science**

Why are the coldest temperatures at the lowest 50 km height from the surface of the Earth, occur generally at tropical tropopause?

*November 9, 2016*

**Math**

T = 80-8t

*November 9, 2016*

**Trig**

or, recall that u dot v = |u| * |v| * cos(theta)

*November 9, 2016*

**Calculus**

yes, but there's not much to solve at that point. Just evaluate the expression: 2*12 - 3*5

*November 9, 2016*

**MATH**

yes

*November 9, 2016*

**MATH**

m - 7 < 6 Nope. ADD 7 to both sides. n - 8 > 5 correct How could you get this one right, and miss the others? Guessing? p + 5 < 10 Nope. Subtract 5 from both sides bus problem. correct

*November 9, 2016*

**Math**

well, 88 ft/s is 60 mi/hr So, about half that.

*November 9, 2016*

**math**

Clearly there were 300 boys and 400 girls.

*November 9, 2016*

**math**

no way to tell without some measure of the relative number of boys and girls. If there were 6 girls and 7 boys, then 2/13 If there were 60 girls and 7 boys, then 11/67 try to post correct problems if you want correct answers.

*November 9, 2016*

**MATHS**

EF is the average of the two base lengths: (AB+CD)/2

*November 9, 2016*

**calc**

You're in calculus and can't sketch linear functions? If you type in the integrals as I showed them, wolframalpha.com understands the notation. For example http://www.wolframalpha.com/input/?i=%E2%88%AB%5B-2,6%5D+%7Cx-1%7C+dx

*November 9, 2016*

**calc**

Just use the power rule for these. ?[1,4] 2x+3 dx = x^2+3x = 24 Recall the definition of |n|: = n if n >= 0 = -n if n < 0 ?[-2,6] |x-1| dx has to be broken up at x=1, so you get ?[-2,1] -(x-1) dx + ?[1,6] (x+1) dx = 17

*November 9, 2016*

**Algebra**

they are both parabolas. #1 opens up, so its range has a minimum #2 opens down, so its range has a maximum So, just find the vertex; that defines the closed end of the range.

*November 9, 2016*

**Advance Quantitative Reasoning**

Huh. You really need to study them. Try law of sines: c/sinC = b/sinB law of cosines uses two sides and their included angle to find the 3rd side.

*November 9, 2016*

**Math**

Read what you posted. Fix it so it makes sense and try again.

*November 9, 2016*

**algebra**

(L-5) = 1/4 (K-5) L+K = 110 Now just solve. wait -- by 1/4 as young, do you mean 4 times as old? That could be a game changer...

*November 9, 2016*

**math**

as always, 2 times (length+width) = 24 ft + 84 in.

*November 9, 2016*

**math**

4/5 as much gas means 5/4 as much distance

*November 9, 2016*

**MATH**

well, twice the distance would be 2 inches, right? You have (375/200) times the distance, so ...

*November 9, 2016*

**math**

well, start with n Then n+12 then 2(n+12) then ... finally, solve the equation for n

*November 9, 2016*

**Pre Calc**

twice what amount? Read what you posted, and fix it so it makes sense.

*November 9, 2016*

**Maths**

(12000/400) * 9/4 minutes

*November 9, 2016*

**Maths**

5.14999999999999999999999999999994

*November 9, 2016*

**math**

342/14 round up if needed.

*November 8, 2016*

**Algebra 2**

well, did you graph the lines of the constraints, and shade the appropriate areas? This web site will solve the problem and even graph the solution if you want: http://www.zweigmedia.com/RealWorld/LPGrapher/lpg.html

*November 8, 2016*

**Math/algebra**

one expression is 10+5h

*November 8, 2016*

**Calculus**

You forgot the chain rule. F'(x) = ?(1+(x^2)^3)*(2x) - ?(1+x^3)*(1) F'(4) = ?(1+4096)(8)-?(1+64) visit this url and scroll down about halfway -- there is a good example with variable limits of integration. https://en.wikipedia.org/wiki/Leibniz_integral_rule

*November 8, 2016*

**math**

if the fractional part is less than 0.5, round down.

*November 8, 2016*

**Math**

2(2.5+2*.3 + 1.2+2*.3) = 9.8m or, the original perimeter plus two sides of each of the the four 30cm squares on the corners: 2(2.5+1.2) + 4(2*0.3) = 9.8

*November 8, 2016*

**math**

If the initial deposit was x, then compare the interest: .06(x+12000) = .05x + 1100 x = 38000

*November 8, 2016*

**math**

(3 3/4)(1 5/6) = 6 7/8

*November 8, 2016*

**Maths**

330m/s * 6s = 1980 m

*November 8, 2016*

**intermediate algebra**

since time = distance/speed, 24/s = 19/s + 1

*November 8, 2016*

**Maths**

total parts water: 2+3 total parts vinegar: 1+1 final ratio is 5:2

*November 8, 2016*

**Physics**

W = J/S = N-m/s So, in t seconds, 250*9.8*25/t = 4000

*November 8, 2016*

**Calculus AB - PS**

Rats. I made a typo near the top of #2. dy/dt = 1/(3?x^2) dx/dt (a) at x=8, 1 = 1/(3*4) dx/dt so, dx/dt = 12 at x=8, not 6. You will have to use that in the other parts. Also, in part (c) I made a typo. It should be sec^2? d?/dt = (-2/3)x^(-5/3) dx/dt, so d?/dt = -36/160

*November 8, 2016*

**Calculus AB**

(a) If the man is x feet from the light pole, and his shadow has length m, then using similar triangles. (x+m)/30 = m/6 In like wise, if the child's shadow has length c, then (x+10+c)/30 = c/3 So, we need to show that x+m > x+10+c when x=90 90+m=5m 90+10+c = 10c m=90/4...

*November 8, 2016*

**geometry**

Just like all the related questions below, The x,y distances from E to F are (10,-5) If G is 1/5 of the way from E to F, add 1/5 of the difference to E. G = (-4,9)+(2,-1) = (-2,8) If G is at the other end, subtract those values from F.

*November 8, 2016*

**Math**

(3.5)(2 2/5)(2.5-0.25) = 18.9 m^3 and it was probably concrete, not cement...

*November 8, 2016*

**math fraction**

It would look like a handful of candies, 1/3 of which were red. If there were n M&Ms, then n/3 would be red.

*November 8, 2016*

**Science**

If you've ever dropped sodium into water, you know that the reaction is violently exothermic.

*November 8, 2016*

**Maths**

f^2/g^2 = f^2 g^-2

*November 8, 2016*

**Math**

If the sum starts at the (k+1)st odd number, its sum is (k+288)^2 - k^2 = 576k + 82944 When k=432, the sum is 331,776 = 24^4 How you'd find that algebraically I have no clue.

*November 8, 2016*

**Math**

Since ??F = 8yk ? 0, F is not conservative.

*November 8, 2016*

**Math**

Did you not read what I wrote? g(0) is not defined, so f/g cannot be defined there. But x?0 is not one of the choices, so something is amiss.

*November 8, 2016*

**Math**

f/g = (|x|-1)/(1/x) = x(|x|-1) It would appear that the domain is all real x, but since g(0) is undefined, we have to exclude x=0. But x?0 is not one of the choices. Is there a typo somewhere? (f?g)(x) = f(g(x)) f(g) = (|g|-1) = (|1/x|-1) Again, x?0, so you are correct.

*November 8, 2016*

**Feelings**

about average

*November 8, 2016*

**Math**

You really need to start using parentheses online, to make things clear: 3/(x^2+x-2) - 1/(x^2-1) = 7/(2x^2+6x+4) Set everything over a common denominator of 2(x-1)(x+1)(x+2). Then, excluding the values of x = -2,-1,1 You just need to find 9-3x = 0

*November 8, 2016*

**maths**

(7/2)/(1/4) = 7/2 * 4 = 14 There are 7 half-liters. Each one contains 2 1/4-liters.

*November 8, 2016*

**Calculus**

Always be on the lookout for trick questions... Develop your inner laziness!

*November 8, 2016*

**Calculus**

Note that the series is collapsing. All the terms except the first and the last cancel out! (1/4 - 1/5) + (1/5 - 1/6) ... + (1/99 - 1/100) = 1/4 - 1/100

*November 8, 2016*

**algebra**

see related questions below. Add up your total so far. How many more to have 5*88 at the end?

*November 8, 2016*

**Math**

You are correct, but why list the values twice?

*November 8, 2016*

**Math**

Do you mean F(x,y) = e^(2x) + x^(2)yi + e^(2y) ? xy^2 j ? If so, then F•dr = (e^(2x) + x^2y) dx + (e^(2y) ? xy^2) dy That makes My = x^2 Nx = -y^2 ?F.dr = -??x^2+y^2 dy dx Using polar coordinates, that is just -??r^2 * r dr d? inside the circle: r = [0,2] ? = [0,2pi]

*November 8, 2016*

**Differential calculus**

Since the distance from the vertex to the directrix is 4, then the standard parabola x^2 = 4py has p=4. So, with the translation of the vertex to (3,-4), and the directrix above the vertex, the parabola opens downward, so the equation is (x-3)^2 = -16(y+4) confirmed at http://...

*November 8, 2016*

**Algebra**

well, x = 5y-19 use that in 7x-2y=32

*November 8, 2016*

**math**

2x^-5 = 2/x^5 2x^(-3/4) = 2/x^(3/4) a negative exponent just means shifting the value between numerator and denominator. Note that this also means that 2/x^(-2) = 2x^2 since that is 2 / (1/x^2) = 2 * x^2/1 = 2x^2

*November 8, 2016*

**Calculus**

Just substitute 6 for 1.8 in your time function. You will find that the shortest time is to boat all the way. A little analysis will show you that if the boat is faster than the running, the boat is the best way. If the ratio of the boat:run speed is k, then the distance ...

*November 8, 2016*

**science**

depends how far it slides. Just note the change in PE: mgh

*November 8, 2016*