Saturday

April 19, 2014

April 19, 2014

**Branches of Math**

**Recent Math Questions**

Post a New Question | Current Questions

**Math**

r/h = sin(a) v = 1/3 pi r^2 h = 1/3 pi h^3 sin(a)
*Monday, April 7, 2014 at 3:34pm*

**Math**

A survey about the student government program at a school finds that of 245 students: • 218 students like the program • 27 students think the program is unnecessary If a circle graph were made from this data, what would the measure of the central angle be for the ...
*Monday, April 7, 2014 at 3:32pm*

**math**

all those angles are the standard ones you should know. cot pi/3 = 1/√3 csc pi/3 = 2/√3 cos pi/4 = 1/√2 plug it in and you have (1/√3 + 2/√3)/(1/√2) = √6
*Monday, April 7, 2014 at 3:32pm*

**Math (check)**

thank you!
*Monday, April 7, 2014 at 3:29pm*

**math**

the two legs are a and b, and the hypotenuse is √(a^2+b^2). So, assuming a,b > 0, So, in QII, sin2x = b/√(a^2+b^2) cos2x = -a/√(a^2+b^2) sin^2(x) = (1-cos2x)/2 = (1+a/√(a^2+b^2))/2 = (a+√(a^2+b^2)) / 2√(a^2+b^2) and similarly for cosx
*Monday, April 7, 2014 at 3:29pm*

**Math**

What is the number of tens for 599
*Monday, April 7, 2014 at 3:13pm*

**math**

if tan 2x= -b/a, pi/2 <=2x<=pi, then determine an expression for sinx cosx in terms of a and b. *please show the calculation
*Monday, April 7, 2014 at 3:12pm*

**math**

determine the exact value of (cot pi/3) + (csc pi/3) / (cos pi/4). how is this calculated? i mean the steps to get the exact value?
*Monday, April 7, 2014 at 3:10pm*

**math**

As a fundraiser a school club is sellin posters. The printer charges a $24 set up fee plus $o.20 for each poster. Then the cost y in dollars to print is given by the linear equation y=0.20x+24 A. The printing of 50 posters cost? The printing cost of 100 posters cost? B. Find ...
*Monday, April 7, 2014 at 2:58pm*

**math**

1 rotation = 360° = 2π radians at 7:00 the minute hand is on the 12 (straight up) and the hour hand has moved 7/12 of a rotation (7/12)(2π) = 7π/6 radians ---> or 210° so the smaller angle between the two hands = 2π - 7π/6 = 5π/6 ...
*Monday, April 7, 2014 at 2:57pm*

**math**

πd * 5 = 3.14 *16 * 5 = 251.2 Yep!
*Monday, April 7, 2014 at 2:38pm*

**math**

A grandfather clock shows a time of 7 o’clock. What is the exact radian measure of the angle between the hour hand and the minute hand? how is it calculated?*
*Monday, April 7, 2014 at 2:38pm*

**math**

B. 251.2
*Monday, April 7, 2014 at 2:34pm*

**math**

There are many ways, square with 10m sides, rectangle 2m by 18m, etc….
*Monday, April 7, 2014 at 2:34pm*

**math **

Please answer ASAP.. Awheel has a diameter of 16 cm. Approximately how far does it travel in 5 revolutions? A. 502.4 cm B. 251.2 cm C. 100.48 cm D. 80 cm
*Monday, April 7, 2014 at 2:32pm*

**Math**

It would depend on how you were measuring the temperature. There are two factors operating here. First, the water does lose heat. Second, the body adapts to the temperature, so even without losing heat, the water does not seem as hot. If only a thermometer is being used, that ...
*Monday, April 7, 2014 at 2:29pm*

**Math (check)**

Interpretation #1 : Slant height is the edge of the pyramid Consider the right-angled (internal) triangle formed by the height , half the diagonal of the base and hypotenuse being the slant height. let the slant height be x let the diagonal of the base be d d^2 = 1^2 + 12^2 = ...
*Monday, April 7, 2014 at 2:26pm*

**math**

3/10
*Monday, April 7, 2014 at 2:25pm*

**math**

hgcfy89uygyu
*Monday, April 7, 2014 at 2:24pm*

**Math**

I labelled the position of the church as C. angle C = 85° by the sine law: CP/sin35 = 600/sin85 CP = 600sin35°/sin85° = appr 345.5 m you do CQ
*Monday, April 7, 2014 at 2:02pm*

**Math (check)**

what is the slant height for the given pyramid to the nearest whole unit? with a pyramid base of 12cm and a height of 8cm. MY ANSWER: 14
*Monday, April 7, 2014 at 1:57pm*

**Math**

Erin has 36 Julia has 2/3 as many as Erin ---> she has (2/3)(36) or 24 Julia also has 1/3 as many as Robert 24 = (1/3)(Robert) Robert has 72 Erin has 36 Julia has 24 Robert has 72 for a total of 132
*Monday, April 7, 2014 at 1:56pm*

**math**

how do i build a rectangler pen using 40 meters
*Monday, April 7, 2014 at 1:46pm*

**Math**

Two towers P and Q are 600m apart with P being due east of Q. A church is on a bearing of 210 degrees from P and 125 degrees from Q. Find the distance of the church from P and Q.
*Monday, April 7, 2014 at 12:56pm*

**Math **

Julia has 1/3 has many stamps as Robert and also 2/3 as many stamps as erin. if erin has 36 stamps, what is the total number of stamps that the 3 children have?
*Monday, April 7, 2014 at 12:31pm*

**Math**

Find the volume of a right circular cone of height h and semi-vertical angle a (Hint: Rotate about the x-axis).
*Monday, April 7, 2014 at 12:11pm*

**Math**

So I have some questions that start with Do the data sets have a positive, a negative or no correlation? Can anyone help explain what this means? An example is "The amount of time spent in the bathtub and the temperature of the bath water." I am confused, thank you.
*Monday, April 7, 2014 at 12:07pm*

**Bridge Math**

The inequality 2003-09-04-00-00_files/i0280000.jpg models all of the combinations of scores of 20 and 30 points that will give a total greater than 400 points in a game. What is not true about the values for x and y?
*Monday, April 7, 2014 at 12:02pm*

**Math (?)**

It would help if you proofread your questions before you posted them. Insufficient data.
*Monday, April 7, 2014 at 11:54am*

**math**

We cannot help unless you state the specific problem.
*Monday, April 7, 2014 at 11:48am*

**math**

need help with math assessment lesson 7
*Monday, April 7, 2014 at 11:19am*

**math-urgent**

Sample space ={1,2,3,4,5} p(1)=0.1, p(2)=0.2 and p(3)=p(4)=0.05. Assume that A={1,3,5} and B={2,3,4}. Find p(5). Find p(A^c). I need help with this question. It is a probability question. please help.
*Monday, April 7, 2014 at 10:49am*

**Math**

Thinking of the doubling rate, we can see that after t hours, the population is P(t) = 50 * 2^(2t) = 50*4^t So, we want 50*4^t = 1000000 4^t = 20000 t log4 = log 20000 t = log20000/log4 = 7.14 hours
*Monday, April 7, 2014 at 10:33am*

**Math**

How about this pattern term(1) = 6 = 3(2^1) term(2) = 12 = 3(2^2) term(3) = 24 = 3(2^3) term(4) = 48 = 3(2^4) .... term(23) = .... = 3(2^23) term(n) = .....
*Monday, April 7, 2014 at 8:04am*

**Math**

6,12,24,48,96...... How can you define the nth term
*Monday, April 7, 2014 at 7:51am*

**math**

how about .15 * 63.00 = ?
*Monday, April 7, 2014 at 4:39am*

**Statistics / Math**

Calculate the standard deviation for: 10, 20, 30 to the nearest tenth presuming a sample
*Monday, April 7, 2014 at 12:41am*

**Discrete Math**

just make your usual Venn diagram and start labeling the intersections.
*Monday, April 7, 2014 at 12:20am*

**businss math**

c
*Sunday, April 6, 2014 at 11:41pm*

**math**

The wheelers' bill at a restaurant is $63.00.How much money should Mr.Wheeler leave as a tip 15%?
*Sunday, April 6, 2014 at 11:35pm*

**Discrete Math**

There are 150 students taking Discrete Mathematics II, Calculus II, and Physics I courses. Of these 51 are taking Discrete Mathematics II, 111 are taking Calculus II, and 63 are taking Physics I. There are 41 taking Discrete Mathematics II and Calculus II, 32 students taking ...
*Sunday, April 6, 2014 at 11:29pm*

**Math age problem**

James is 35 years older then chris. If chris 55 years old now, how old is chris
*Sunday, April 6, 2014 at 10:51pm*

**Math**

Thanks
*Sunday, April 6, 2014 at 10:30pm*

**Math**

2.7^3 = 19.683 15 * 19.683 = 295.245
*Sunday, April 6, 2014 at 10:14pm*

**Math**

The volume of the cylinder is 15 cubic inches. If all the dimensions are multiplied by 2.7 what is the new volume? My Answer- 295.245
*Sunday, April 6, 2014 at 10:09pm*

**3rd Grade Math**

solve a simpler problem
*Sunday, April 6, 2014 at 10:01pm*

**algebra or math**

Explain in words how to write an equation that is part one: parallel and then also part two: perpendicular to the equation y=2/3x-4 passing through the point (-2,-5). Write your answer in standard form.
*Sunday, April 6, 2014 at 9:56pm*

**Math**

I am sure you meant: Q(t) = 7000/(1 + 249 e^(-.6t) ) Q(10) = 7000/(1 + 249 e^(-.6(10) ) ) = appr 4328
*Sunday, April 6, 2014 at 9:48pm*

**Math**

Q(t) = 200 (1/2)^(t/14.2) or Q(t) = 200(.5)^(.0704t) Q '(t) = (200/14.2) (.5)^(t/14.2) so when t = 21.5 Q ' (t) = (200/14.2) (.5)^(21.5/14.2) = 4.931 g/day
*Sunday, April 6, 2014 at 9:43pm*

**Math**

we have already done a half life one but anyway ds/dt = k s ds/s = k dt ln s = k t + c when t = 0, ln si = c si is initial size ln s = k t + ln si ln (s/si) = k t s/si = e^kt 2 = e^k(30 min) ln 2 = 30 k k = .0231 1,000,000/50 = e^.0231 t ln (20,000) = .0231 t t = 428.6 = 429 ...
*Sunday, April 6, 2014 at 9:34pm*

**math**

P = Po(1+r)^n Po = $10,000 r = 8%/100% = 0.08 = APR expressed as a decimal. n = 1comp/yr. * 18yrs. = 18 Compounding periods. Solve for P.
*Sunday, April 6, 2014 at 9:19pm*

**Math**

Correction: c. % Grade = Slope expressed as a percentage.
*Sunday, April 6, 2014 at 9:02pm*

**Math**

.5 = e^-k T ln .5 = - k T T = -.693/-k = .693/k b) T = .693 / .0001074 = 6454 years
*Sunday, April 6, 2014 at 9:01pm*

**Math**

The growth rate of Escherichia coli, a common bacterium found in the human intestine, is proportional to its size. Under ideal laboratory conditions, when this bacterium is grown in a nutrient broth medium, the number of cells in a culture doubles approximately every 30 min. (...
*Sunday, April 6, 2014 at 9:00pm*

**Math**

Phosphorus-32 (P-32) has a half-life of 14.2 days. If 200 g of this substance are present initially, find the amount Q(t) present after t days. (Round your growth constant to four decimal places.) How fast is the P-32 decaying when t = 21.5? (Round your answer to three decimal...
*Sunday, April 6, 2014 at 8:59pm*

**Math**

The length (in centimeters) of a typical Pacific halibut t years old is approximately. (b) How fast is the length of a typical 9-year-old Pacific halibut increasing? (c) What is the maximum length a typical Pacific halibut can attain?
*Sunday, April 6, 2014 at 8:55pm*

**Math**

A radioactive substance decays according to the formula Q(t) = Q0e−kt where Q(t) denotes the amount of the substance present at time t (measured in years), Q0 denotes the amount of the substance present initially, and k (a positive constant) is the decay constant. (a) ...
*Sunday, April 6, 2014 at 8:54pm*

**Math**

The percentage of a certain brand of computer chips that will fail after t years of use is estimated to be P(t) = 100(1 − e−0.12t ). What percentage of this brand of computer chips are expected to be usable after 3 years? (Round your answer to one decimal place.)
*Sunday, April 6, 2014 at 8:53pm*

**Math**

During a flu epidemic, the number of children in the Woodbridge Community School System who contracted influenza after t days was given by the following. Q(t) = 7000/1+249 e−0.6 t (b) How many children had the flu after 10 days?
*Sunday, April 6, 2014 at 8:52pm*

**Math**

a. Y/X = Y/2.5 = 0.06 Y/2.5 = 0.06 Y = 0.15 Miles = 792 Ft. b. Y/X = Y/90 = 0.06 Y = 90 * 0.06 = 5.4 Miles = 28,512 Ft. c. % Grade = Slope expressed as a decimal.
*Sunday, April 6, 2014 at 8:40pm*

**Math**

I would consider it a "combination" , assuming that the order that you choose the appetizers should not matter Number of ways = C(4,2) x C(5,1) = 6x5 = 30
*Sunday, April 6, 2014 at 8:16pm*

**MATH**

A polynomial must have a non-negative integer exponent. A and B contain square roots or exponents of 1/2 D: 11/(√x)^2 = 11/x or 11 x^-1 so none is a polynomial C: x - √11 yup, I would go with that one
*Sunday, April 6, 2014 at 8:10pm*

**math**

P = Po(1+r)^n Po = $8500 r = (12%/4)/100% = 0.03 = Quarterly % rate expressed as a decimal. n = 1yr * 4comp/yr. = 4 compounding periods. Plug the above values into the given Eq and sole for P.
*Sunday, April 6, 2014 at 8:03pm*

**MATH**

Which expression is a polynomial???? A: 11 0ver the square root of x B: square root of 11 times x C: x - square root 11 D: 11 over the square root of x to the 2nd power (sorry I am not sure how to insert square root symbols or fractions, so u have to imaging its there) thank ...
*Sunday, April 6, 2014 at 7:37pm*

**Math**

Alex's favorite restaurant is a buffet-style Chinese restaurant downtown. Each time he goes, he chooses 2 appetizers and 1 entree. If the restaurant has four appetizers and 5 entrees to choose from, how many, times could Alex go to the restaurant without choosing the same ...
*Sunday, April 6, 2014 at 7:20pm*

**math**

cost is rate * distance. If the distance from home to A is x, then from home to B is 6-x. So, since the costs are the same, 50x = 75(6-x) 50x = 450-75x 125x = 450 x = 3.6 So, (C)
*Sunday, April 6, 2014 at 7:15pm*

**math**

You're welcome, Thomas.
*Sunday, April 6, 2014 at 7:04pm*

**Math**

since all dimensions are 1.6 times as big, the volume (multiplying all three dimensions) is increased y a factor of 1.6^3. 92 * 1.6^3 = ?
*Sunday, April 6, 2014 at 6:55pm*

**math**

thank you, Ms. Sue
*Sunday, April 6, 2014 at 6:37pm*

**math**

0.5x + 0.25x + 0.2x + 5000 = x 0.95x + 5000 = x 5000 = 0.05x 100,000 = x
*Sunday, April 6, 2014 at 6:29pm*

**math**

Mr. Benedict left half of his estate to his wife, one-fourth to his son, one-fifth to his daughter and the remainder, $5000 to his college. What is the total amount left by Mr. Benedict? a. $ 9,250 b. $ 10,000 c. $ 16,000 d. $ 50,000 e. $ 100,000 please answer and explain
*Sunday, April 6, 2014 at 6:25pm*

**Math**

http://www.google.com/webhp?source=search_app#q=mathematical+concepts+string+art
*Sunday, April 6, 2014 at 6:25pm*

**Math**

What are mathematical concepts are used to make string art?
*Sunday, April 6, 2014 at 6:21pm*

**math**

You're welcome.
*Sunday, April 6, 2014 at 6:15pm*

**math**

ok , thank you
*Sunday, April 6, 2014 at 6:14pm*

**math**

Cutting 2.5 inches from each end of the cardboard: 9 - 5 = 4 12 - 5 = 7
*Sunday, April 6, 2014 at 6:13pm*

**math**

why use 4 x 7
*Sunday, April 6, 2014 at 6:02pm*

**math**

4*7*2.5 = ?
*Sunday, April 6, 2014 at 6:00pm*

**math**

A rectangular piece of cardboard 9" x 12" is made into an open box by cutting a 2 1/2" square from each corner and bending up the sides. Find the volume of the box if no allowance is made for overlapping of the edges. a. 70 cu. in. b. 154 3/8 cu. in. c. 195 cu. ...
*Sunday, April 6, 2014 at 5:50pm*

**Math**

Please help!
*Sunday, April 6, 2014 at 5:21pm*

**CHEMISTRY**

.........A ==> 2B I....0.154.....0 C........-x....2x E...0.154-x....2x Substitute the E line into Kc expression and solve for x and 0.154-x. I don't know if the prof expects you to answer this with math (working out the above equation) or by reason but the math should ...
*Sunday, April 6, 2014 at 5:14pm*

**Math **

A triangular prism has a volume of 92 in.³ if all dimensions are multiplied by 1.6 what is the new volume?
*Sunday, April 6, 2014 at 4:59pm*

**math**

Yes! You're welcome.
*Sunday, April 6, 2014 at 4:44pm*

**math**

I understand now, like a triangle a^2 + b^2 = c^2 thank you
*Sunday, April 6, 2014 at 4:42pm*

**math**

Pythagorean Theorem: 40^2 + b^2 = 50^2 1,600 + b^2 = 2,500 b^2 = 900 b = 30
*Sunday, April 6, 2014 at 4:35pm*

**math**

Two stations, A and B, are located six miles apart on a railroad. The rates of cartage of coal are 50 cents per ton per mile from A and 75 cents per ton per mile from B. At a certain consumer's home, located on the railroad between A and B, the cost for cartage is the same...
*Sunday, April 6, 2014 at 4:35pm*

**math**

A 50 foot ladder is placed against a building so that it touches a point 40 feet above the ground. The distances ( in feet ) from the foot of the ladder to the building is a. 10 b. 20 c. 30 d. 45 e. 60 please answer and explain
*Sunday, April 6, 2014 at 4:30pm*

**Math**

there are only 3 colors, so the 4th sock must match one of the first three.
*Sunday, April 6, 2014 at 4:19pm*

**Math**

5000
*Sunday, April 6, 2014 at 4:14pm*

**Math**

You are about to leave for vacation, but you forgot your socks! You go back to your room but lights are out, can't see. You remember that in your draw you have 10 pair black, 10 pair white and 11 pair blue all mixed up. How many socks do you need to take out to be SURE you...
*Sunday, April 6, 2014 at 4:00pm*

**Math (?)**

Measure them with ruler or measuring tape? Insufficient data to answer second question.
*Sunday, April 6, 2014 at 2:13pm*

**Math (Trigonometry)**

secx + tanx = 3/2 secx = 3/2 - tanx sec^2 x = 9/4 - 3tanx + tan^2 x tan^2 x + 1 = 9/4 - 3tanx tanx = 5/12 so, sinx = 5/13 #2 is quite similar. tan^2 x + secx = 5 sec^2 x - 1 + secx = 5 sec^2 x + secx - 6 = 0 (secx+3)(secx-2) = 0 in QI, then, cosx = 1/2
*Sunday, April 6, 2014 at 1:33pm*

**Math**

well, just figure out the formula for the area: a = (w)(2w)(5w-15) for positive dimensions, w > 3 With no other restrictions, the range will be all positive real numbers.
*Sunday, April 6, 2014 at 1:29pm*

**Math**

1*1*C(6,2) = 15 extra credit: why did I multiply by 1 -- twice!? also, proofread before posting. I assume you meant the same topping can't be used twice for 1 pizza.
*Sunday, April 6, 2014 at 1:23pm*

**Math**

correct
*Sunday, April 6, 2014 at 1:21pm*

**Math**

1000000 people/66000 mi^2 = 1000/66 people/mi^2 That's a lot less than any of the proposed densities, so (A) assuming the cited figures actually apply to Florida...
*Sunday, April 6, 2014 at 1:20pm*

**Math/Physics**

when Tyson left at 11:00, Rashad had already gone 200km, so the two were 580 km apart. They approached each other at 180 km/hr, meaning they met in 3 2/9 hours. So, by the time they met at 2:13:20, Tyson had gone 257.8 km.
*Sunday, April 6, 2014 at 1:18pm*

**Math**

Please help
*Sunday, April 6, 2014 at 12:51pm*

**math**

20,002
*Sunday, April 6, 2014 at 12:28pm*

**Math/Physics**

Problem Question: Rashad started The 780km drive from Sault st. Marie to Ottawa at 09:00. His average speed was 100km/h. Two hours later Tyson left Ottawa for Sault St. Marie. He drove at 80km/h on the same highway. How far from Ottawa, and what time of day did they meet?
*Sunday, April 6, 2014 at 12:26pm*

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