Thursday

April 24, 2014

April 24, 2014

Total # Posts: 21,976

**Math**

150 * 3 * 1/2 * density.of.snow

**Math**

x+y = 3/2 x-y = 5/12 2x = 11/12 ...

**Math**

C MN and PR are not corresponding sides

**MATH TRIGO-PLSSS ANSWER CLEARLY COZ IM VERY LOW IN**

Draw a diagram. Let T be the top of the tower M be the top of the monument A be the base of the tower B be the base of the monument ∠TBA = 31° so, 145/TB = sin 31° Since ∠TBM = 59° ∠MTB = 18°, ∠TMB = 103° The desired height (MB) is f...

**algebra**

c(p) = 50+2p

**algebra**

well, is (2+3)^2 = 2^2+3^2 ? Hint: (x+y)^2 = (x+y)(x+y) expand that and compare to x^2+y^2

**math**

take a look at http://www.wolframalpha.com/input/?i=3%28x-4%29^2+-3+

**math**

since there are 5 choices for each digit, there are 5^8 choices for the number

**Math**

if the initial value is v, v - .35(2) = 13520 Now, knowing v, after n years the car is worth v(1 - .35n) Note that the car is fully depreciated after only 3 years, if the depreciation is 35% of the full value each year.

**math trig**

If B is at distance x from the tower of height h, h/x = tan 46° h/(x+80) = tan21° so, eliminating x, we get h/tan46° = h/tan21° - 80 Now just solve for h

**MATH :DD**

2(5+.12(m-200)) < 30 minimum? 0 of course.

**Maths**

x = (y-3)/5 d = (c+2)/5 a = (v-u)/t

**science**

neutral must have 11 so, the +1 ion has only 10 electrons p+n = 23 p = atomic number

**science**

an ion has unbalanced charge, so what do you think?

**trig**

one resultant

**statistics**

You can plug in your data and play around with it at http://davidmlane.com/hyperstat/z_table.html

**math**

y-8 = -2(x-6)

**Physics**

the outer tire travels 2pi*1.7 = 10.68 m farther than the inside tire Since the radius is .4 m, that's an extra 4.25 revolutions per lap Since a lap takes 20.2 seconds, that's an extra 2pi*4.25 rad/20.2 s = 1.32 rad/s

**Math**

y-1 = 3(x-5) y = 3x-14

**Geometry**

y+4 = 2(x-8)

**Math**

y = -4

**Chemistry**

PV/T is constant So, if we have 2P, we need 2T to hold the ratio. (T, of course is Kelvin)

**Finite Math**

plug in your data at http://davidmlane.com/hyperstat/z_table.html

**science**

since PV/T is constant, if P increases by a factor of 4.69/4.6, T decreases by a factor of 4.6/4.69. T is Kelvin, of course.

**arithmetic**

n lines can intersect in n(n-1)/2 points

**Maths**

you know the general shape of a cubic. The only real trick is finding where the roots are, then sketch a cubic curve through the roots. A little synthetic division shows that f(x) = (x-1)(x-3)(x-3) So, draw your cubic curve so that it crosses at x=1 and is tangent at x=3.

**introduction to catering**

My daughter, who has been in the food service industry for several years, and done much catering, says: know your market have financial knowledge to control the costs

**Physics**

conservation of momentum says that the result is 2050(2.3i+0j)+1200(0i+4.5j)+1600(10i+j) = (2050+1200+1600)(ai+bj) 4715i+5400j+16000i = 4850(ai+bj) 20715i+5400j = 4850(ai+bj) 4.27i+1.11j = ai+bj speed is 4.42 m/s direction E14.5°N

**Maths**

5600(1+.095/2)^(2*3) = 7397.96

**Math**

PQ has slope -2/9 RS has slope -1 not parallel rule: subtract 5.10 each time

**Geometry**

slope: 14/17 y-8 = 14/17 (x-10) y = 14/17 x - 4/17

**Math**

greater by a factor of 4, in the amount of 48π

**Math**

No idea about rice cakes, but if we're talking about pizzas, greater by a factor of (5.83/0.6)^2 The area is greater by (5.83^2 - 0.6^2)π

**MATH**

(f+g)(x) = f(x)+g(x) = -6x-1 + 4x^2 = 4x^2-6x-1 -24x^3-4x^2 = (fg)(x) = f(x) * g(x) -24x^2-1 is not related.

**MATH**

(fg)(x) = f(x)*g(x) = 4x^2(-6x-1) = -24x^3-4x^2

**Maths**

3/(2/9) = 3 * 9/2 = 13 1/2

**Trigonometry**

3(cos^2θ - sin^2θ) 3cos(2θ)

**Trigonometry**

2sinx = 3/√2 + cosx 4sin^2 x = 9/2 + 3√2 cosx + cos^2 x 4 - 4cos^2 x = 9/2 + 3√2 cosx + cos^2 x 5cos^2 x + 3√2 cosx + 1/2 = 0 cosx = [-3√2 ± √(18-10)]/10 = (-3√2 ± 2√2)/10 = -√2/10 or -1/√2 now just take...

**math**

If the front of the log is at distance d, and the log has length x, then 30/d = tan 16.7° 30/(d+x) = tan 14° eliminate d and we have 30/tan16.7° = 30/tan14° - x now just solve for x, the length of the log.

**Trigonometry**

since cos2x = 2cos^2 x - 1, we have 2cos2x - 5/2 sin2x - 4 = 0 or 4cos2x - 5sin2x - 8 = 0 4cos2x = 5sin2x + 8 16cos^2 2x = 25sin^2 2x + 80sin2x + 64 16 - 16sin^2 2x = 25sin^2 2x + 80sin2x + 64 41sin^2 2x + 80sin2x + 48 = 0 now just solve for sin2x using the quadratic formula.

**math**

lots of similar and simple problems. Have any solutions to offer that we can check?

**Math**

net displacement is 1 N and 3 W. Use the Pythagorean Theorem (distance formula) to figure the diagonal distance (hypotenuse)

**Math**

started at 52, increased 22 in 4 years, or 5.5 per year. Looks like B to me. Now use that formula to answer the other parts.

**algebra**

There's only one point for the equation: x = 5/4 I think you left something out.

**math**

g(x) = f(x)+15 = x^2+19+15 = x^2+34 f(x+15) shifts the graph left by 15 units, not up. Something tells me that f(x) = x^2+9, judging from your other efforts.

**calculus**

a = 2t-4, not 2t^2-4

**calculus**

a=2.675543 b=7.23334

**calculus**

pretty easy upper limit of b is 25.15 lower limit of a is 16.23

**calculus**

r' = 2.4/(3t+6) r = 0.8 log(3t+6)+c solve for c at t=0 in 0.8 log6 + c = 3.8 now just plug in t=16 for the final answer.

**calculus**

r' = 2.1/(t+5) r = 2.1 log(t+5) + C at t=0, 3.8 = 2.1 log5 + C C = 3.8-2.1log5 = 0.42 so, r = 2.1 log(t+5)+0.42 now just plug in t=27

**Calculus**

what's the trouble? Straightforward integration: a = ∫[-2.6,2.6] 12e^(3x) dx = 4e^3x [2.6,-2.6] = 9762.41

**Algebra 1**

Looks good. Nice work. We'd much rather see that you are making an effort to solve the problems, rather than just getting someone else to do your assignments. Although, usually the earlier time is mentioned first, as was done in the problem.

**Algebra 1**

OK. You've given some possible answers. Which one do you think is right, and why?

**Algebra 1 - and now, ...**

oof - how about you propose some answers to these problems? Surely you must have some ideas.

**Algebra 1**

do you understand the expressions for the current and proposed plans? Those are just symbols for the words that described the plans. Read the problem carefully, and wherever they give some information, write it down in numbers or symbols. To solve for m, just do the regular st...

**Algebra 1**

for m minutes, current plan: 5.00 + .12(m-200) proposed plan: 30.00 so, we want solve 5.00 + .12(m-200) < 30.00 m < 409

**Algebra 1**

In that case, he gets a $16.80 discount, making his base membership cost $67.20 SO, he gets an additional discount of $19.20 to bring his cost down to $48. At $5/referral, that would mean 4 referrals would do the trick. In symbols, we have 84(.8)-5n < 48 67.20 - 5n < 48 ...

**Algebra 1 - incomplete**

can't say, without knowing whether or not he got any discounts.

**Algebra 1**

79 - highest digit and sum of digits Here's an oldie but goodie. Find the pattern in this sequence: 1 11 21 1112 3112 211213 312213 212223 114213 31121314 ...

**Algebra 1**

well, a 5-gallon bucket costs the same as 4 1-gallon cans. So, if g <= 4, buy cans. If 4<g<=5, but the bucket. Naturally, if g > 5, buy enough buckets so that the remainder is less than 5. Then apply the above rule for the remainder.

**Math**

y = 3(x-3)(x-5) = 3(x-4)^2 - 3 now the answers should be clear. What do you get?

**Business Calc**

19000(1+.03/2)^(2n) = 47500 now just solve for n.

**Algebra**

I' sorry I meant D

**Algebra**

which oft the following types of data s not suited for display on a scatter plot a -- relationship between age and number of books read in a year b -- relationship between height and shoe size c -- relationship between calories consumed and wight d -- relationship between heig...

**algebra**

5% of $84 = $4.20 20% of $84 = $16.80 Assuming no discounts, he needs n referrals, so that 84 - 5n < 48 Adjust that 84 according to how many discounts he achieved.

**MATH :D**

No idea, but lots and lots. The larger the year, the more ways there are to partition it. 1-1-02 all the way to 12-31-43

**Algebra**

which of the following is true bout a trend line for data? a- the minimum data point always lie on the trend line b- every data point must lie on the trend line c- the trend line describes the pattern in the data if one exists d- the trend line includes the effect of all outli...

**Algebra**

4(6x^2-x-2) 4(3x+2)(x-1)

**Math Geometry**

x * (5/4)x = 180 x^2 = 144 ...

**Calculus Help Please!!!**

y' = 8x-6x^2 so, at x=a, y' = 8a-6a^2 = m Use the above info to plug into the point-slope form of the lines. No sweat.

**Math**

The key here is to recognize that opposite angles are supplementary. So, BAD+BCD = 180 2BAD=3BCD, so BCD = 2/3 BAD 5/3 BAD = 180 BAD = 108

**Calculus Help Please!!!**

(c) (15005-10237)/2 = 2384 (d) (16684-12435)/2 = 2124.5 (e) Looks like growth is slowing down

**Algebra - help**

just add them up: 3.1x^2+6x+0.3 4.2x2-5.2x+1 ---------------------- 7.3x^2+0.8x+1.3

**Algebra**

well, just plug it i: S = 4 pi (4x+1)^2 now just expand that

**Math**

n Tn 1 3*1+5 = 8 and so on actually, assuming one choice is correct, only B is a candidate.

**math**

(7y+4)(y-8)

**Math - incomplete**

well, with the four scores given, the average is already 75. I think some info is missing.

**Math**

since the period is 60/3.6 seconds, and reaches a max at t=12 seconds, y = 35cos(2pi/(60/3.6)(t-12))+51 which agrees with your formula. You have found y at t=8 seconds, not 8 minutes.

**math**

(6-4.5)/4.5 = 1/3

**Science**

Felipe made a toy boat out of clay, but it kept sinking in water. He changed the boat's design by making it slightly wider than before. Why did Felipe's newly designed boat float on water? A. He decreased the density by increasing the volume. B. He decreased the densit...

**Trigonometry**

C = 24pi in = 2pi ft (20 ft/s)/(2pi ft/rev) = 10/pi rev/s * 2pi rad/rev = 20 rad/s

**Trig**

no. sinA = 2 sinB

**math**

11/4

**Algebra word problems**

5x+20y = 175 x = 4y+3 Now just solve for x and y

**math**

yes

**math**

-y/6 < 2 y/6 > -2 y > -12

**math**

2/5 n = 4 n = 10

**Algebra 1**

RA = 11 RT = 1

**Math**

since the height of the ball is y = Ho + (tanθ)x - g/(2 (v cosθ)^2) x^2 y = 50 + .1175x - .000563x^2 Just solve for θ in 50 + (tanθ)(420) - 16/(2(120 cosθ)^2) * 420^2 = 0 I get θ = 6.7°

**Algebra**

7x*11x - 2x*3x = 71x^2

**Math**

1/2 dozen, no?

**Polymonial help**

Can you not? My factorization gives the three dimensions. Look at the last choice.

**Polymonial help**

factor the polynomial and you have y(y-6)(y+1) so, as long as y>6 some possible dimensions are 7x1x8 8x2x9 ...

**Math**

compare the times. The time it took to cover 100km at speed s is 100/s That was 1/2 hour more than the time it took to cover 100km at the faster speed, s+10

**Math**

since time distance/speed, 100/s = 100/(s+10) + 1/2 s = 40

**math**

(sum(r) for r=1..n)^2 - (sum(r) for r=1..n-1)^2 = n^3 well, we know that n ∑ r = n(n+1)/2 r=1 so, square that and we have n^2(n+1)^2/4 Sum to n-1 instead of n, and we have (n-1)^2 n^2/4 Subtract to get n^2/4 ((n+1)^2 - (n-1)^2) = n^2/4 (4n) = n^3

**ASCC**

25 m/s / 2.3 m/s^2 = 10.87 s distance = 25t - 1.15t^2 where t = 10.87

**Math**

no diagram. If the angles are alternate interior/exterior angles, then 5x+2 = 3x+28 If they are adjacent angles, then 5x+2 + 3x+28 = 180

**Math Help**

since the bus catches up 175 km in 5 hrs, that's a speed difference of 35 km/hr. So, the bus went 10+35 = 45 km/hr Your solution is in error. It should be 225km/5 hr = 45 km/hr (Also, the units are wrong in your 1st line: 10km/hr * 5 hr = 50 km, not 50km/hr) another soluti...

**Geometry**

That's what I get.

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