Thursday

July 31, 2014

July 31, 2014

Total # Posts: 10,590

**Math**

Yes, the calculation is correct for the net price factor.

**math :)**

You're welcome!

**math**

Hint: a sector is a pie-piece, similar to a slice of pizza. The area of a sector of a given radius is proportional to the central angle. Area of Sector -------------- Area of circle central angle =------------- 360°

**math :)**

You're welcome!

**math**

Do it just like normal subtraction, except that when you borrow 1 degree, it becomes 60 minutes, ... 41-20-26 23-39-56 -------- 17-40-30

**PHYSICS**

Does it come with a diagram?

**chemistry**

Zn+2HCl -> ZnCl2 + H2 5.5 g of Zn = 5.5/65.382 M =0.0841 M 25 ml of 0.05M HCl = 25/1000*0.05 M = 0.00125 M < 0.0841/2 So the quantity of HCl governs. Assuming all HCl is consumed, amount of Hydrogen = 0.00125/2 M = 0.000625 M Convert that to the required temperature and ...

**French :)**

Je vous en prie!

**French**

Give it a try! You must know the name.

**French**

camping is an English word borrowed by the French language which means 1. the activity of camping 2. camp-ground. "Comment s'appelle" is an expression which translates to "what do you call ...." "ce" => this "terrain de camping" =...

**math :)**

You're welcome!

**math**

If the length of one of its sides is x. Then x/2 is half the side. An altitude divides the equilateral triangle into two congruent right triangles, each with half of one side (x/2) as the short side, the altitude as the long side, and the side (x) as the hypotenuse. So by usin...

**math :)**

You're welcome!

**math**

a' ÷ a = b' ÷ b so a' = b' × a / b

**math :) **

You're welcome!

**math**

Do you mean sin-1(0.398) = ? ° ? ' ? " = 23.45320822° multiply the decimal part by 60 =23°27.19249' multiply the decimal part by 60 =23°-27'-11.55" (approx.) =23°-27'-12" (nearest second)

**math**

Every 5 minutes, the minutes hand turns 30° If it turns 360° (from 12 to 12), then the distance is 43.96. You can use proportions to find how much distance the tip travels from 1 to 4.

**math**

If the 7-inch hand goes through a complete circle, it would travel the equivalent of the circumference of a circle of radius 7 inches. Use Circumference = 2πr How far would the tip travel from 1 to 4 o'clock?

**probability**

See response to your previous post: http://www.jiskha.com/display.cgi?id=1369507871

**French**

According to the Petit Robert dictionary, it also stands for vélo tout-terrain, which means mountain-bike. So the meaning can differ from one country to another.

**French**

Véhicule tout-terrain

**Statistics**

Here are some numbers for checking your answer. approximately y=2.3x+23 The correlation coefficient is over 0.99.

**algebra**

Reflection about the y-axis is given by: (x,y)-> r(-x,y)

**Math**

It is a binomial distribution, with p=0.6 (probability of success) q=0.4 (probability of failure) n=5 (number of steps) r=2 or 3 (number of successes) P(n,r)=nCr p^r q^(n-r) P(5,2)=5C2 0.6^2 0.4^3 =(5!)/(3!2!) 0.6^2 0.4^3 = 10(0.36)(0.064) = 0.2304 Similarly, for 3 tails, r=3,...

**simple interest and compund interest.**

It sounds like you have difficulties putting numbers into the formula you gave me, so I will do the first one for you. You can attempt the second one as a confirmation. A=P(1+rt) Since A=amount, so Amount=P(1+rt) P=3000, so Amount=3000(1+rt) r=0.03 (3%), so Amount=3000(1+0.03t...

**simple interest and compund interest.**

A=amount P=principal=$3000 r=0.03 t=number of years, missing from question. Take out your calculator and calculate according to the formula: A=P(1+rt) Here i=5%=0.05/12 (compounded monthly n=6 years = 6*12=72 months P=principal (unknown) A=final amount = $15000. From A=P(1+i)^...

**HealthCare Finance Bonds**

Sorry, meant "going back to IRS"

**HealthCare Finance Bonds**

a. At 12% yield, with 40% going back to IRA, he nets 12%(1-0.4)=7.2% b. and c dependent on answer of a, will give you a chance to try them.

**Statistics**

Here are a few articles that explain what a p-value is, with examples. One of them is a youtube link, if you so prefer. http://www.stat.ualberta.ca/~hooper/teaching/misc/Pvalue.pdf http://www.youtube.com/channel/HCM26EC2x5oEU http://en.wikipedia.org/wiki/P-value

**expressions**

Since the rate of filling is constant, it is a rule consisting of a linear expression. Let H=height, and x=number of days since today (day 0). Since water rises 2 feet per day, today's height, H = 14 feet. So the rule is then H = 14+2x where 2 = additional depth per day 14...

**exponents :)**

You're welcome!

**exponents**

#4 and #5 are both correct. For #8, it is x^8/y^8, since the question requires positive exponents. (You could have written it as x^8y^-8.) 1. 1/125 is 1/5^3. See if you can find the correct answer. 2. d^4*d^6 is d^10, so correction required. 3. the minus sign before the number...

**scientific notation am i doing it right?**

signature.

**scientific notation am i doing it right?**

Sorry, finger faster than the brain, forgot to change since last post.

**scientific notation am i doing it right?**

#1 is correct. The power of 10 refers to the number of positions the decimal point has to be moved, not the number of zeroes. So for #2, it should be 9.82000*100000=982000 Similarly, for #3, 9x10^3=9/1000=0.009 I will leave #4 for you to try.

**scientific notation am i doing it right?**

All correct, well done!

**Sequences**

Find the rule for number 2, which is a geometric series. You can tell if it is a geometric series by dividing any term by the previous. If the quotient is the same, then it is a geometric series. The rule for a geometric sequence is: t(n)=ar^n and r is the quotient by dividing...

**Sequences**

Let the nth term of the arithmetic sequence be t(n)=ax+b then t(1)=a(1)+b=7 t(2)=a(2)+b=12 Subtracting, we find 2a-a=12-7 which gives a=5 Substitute back into the formula, t(1)=5(1)+b=7, so b=2 the complete rule is then t(n)=5x+2 The nineteenth term is therefore t(19)=5*19+2=9...

**polynomials am i doing it right?**

You're on the right track... 1. expand it and write it out when it is a subtraction: (x^4+7x^3+7)-(2x^4-4x^3+1) = x^4+7x^3+7) -2x^4+4x^3-1 = -x^4 + 11 x^3 + 6 2. space out your terms to avoid losing some of them. (3n^3 + n^2 -n -4)+(5n^3 -4n^2 + 11) = 3n^3 + n^2 -n -4 + 5n...

**How to get quick responses to your math questions**

Also, - DO check that the question you are about to post is complete and accurate before pressing the "post" button. - Do not omit parentheses. If the numerator or denominator of a fraction has more than one term, you need parentheses around them when you transcribe ...

**How to get quick responses to your math questions**

Math is a wide subject, ranging from K to 11, college and university. Then there is algebra, trigonometry, geometry, arithmetic, calculus, number theory, ... etc. Not all teachers answer all math questions (many do). If you would give a little more detail on which branch of ma...

**Physics**

Hint: Find the resultant of the two given forces. The third force (which keeps the resultant in equilibrium) is a force which is equal in magnitude to the resultant, but opposite in direction.

**Maths**

Use the property of intersecting chords PA*PB=PC*PD In this case the chords intersect outside of Γ. Also, if T is the tangent to Γ passing through P, then PA*PB=PC*PD=PT²

**math**

Trade discount = $679.95*0.30

**trig**

So on the Cartesian plane, it is in the fourth quadrant, with x-y as (900,-500). Atan(-500/900)= -29° approximately. So the bearing is S61°E.

**Calculus**

Use substitution, p=sin(x), dp=cos(x)dx I=∫ydx =∫cos(x)(2sin(x)-1)^6dx =∫(2p-1)^6 dp Substitute again, u=2p-1, du=2dp I=∫u^6 (dp/2) =u^7/7 ÷2 + C Now back substitute u=2p-1=2sin(x)-1 I=(2sin(x)-1)^7 /14 +C

**Math/ Algebra**

Rewrite the equation in symmetric form x/a + y/b = 1 where a and b are the x- and y-intercepts respectively. y/2 -3x/5 = 1 can be rewritten as: x/(-5/3) + y/2 = 1 Identify the intercepts and graph accordingly.

**Math**

15/20/20 is a successive discount of 15%, followed by 20% on the discounted price, and finally another 20% of the doubly discounted price. For example, $1000 with a trade discount of 15/20/30 would have a final discounted price of $1000*(1-0.15)(1-0.20)(1-0.30)=$476 So the tra...

**Math/ Algebra**

See http://www.jiskha.com/display.cgi?id=1369451313

**Math**

p=probability of scoring (success) = 0.8 q=probability of not scoring (failure = 0.2 Assuming the probability does not change over time and is independent of previous results, then we can apply the binomial distribution: P(7+ out of 8) =8C7*0.8^70.2+8C80.8^8 =0.34+.17 =0.50 (a...

**statistics**

Ah! I see it now. "y (in tens of thousands of dollars)" That might be the culprit.

**statistics**

Did you put $5.13 or 5.13?

**Statistics**

There are different ways to find the regression line. Do you know which one you are supposed to use? It should be around y=-0.6x+310. Try to calculate the coefficients and we can check you answer. Do specify the method, and work details if you can.

**statistics**

If you are working on the computer, you have to get the answer exactly right. It asked for the answer to 2 decimal places. If you put three (3.625), it could mark you wrong. On the other hand, there are two ways to round it to 2 decimal places. Most people round it up when it ...

**Math - please help**

The height is 280 ft. Distance from apex to mid-point of base = 356.1 ft = slant height. Area of one side = (1/2)base*slant-height then choose the correct answer.

**Calculus**

Let f(x)=sqrt(1+6x) then f'(x)=3/sqrt(6*x+1) and f'(0)=3 Thus the slope of the curve is 3 at x=0. f(0)=1 means that the tangent to the curve passes through (0,1)=(x0,y0). So the linearization is y=Ax+B =Slope(x-x0)+y0 =3(x-0)+1 =3x+1 Identify A and B for your answer.

**Maths**

For x near 1, you can use linearlization, which is f(x)=f'(1)(x-1)+f(1) =(1/8)x+f(1) Therefore, within the errors of the linearization, f(x)-f(1) = (x-1)/8 (approximately)

**geometry - missing information**

To scale or not, we don't get to see it. So we depend on you to describe the figure.

**please answer simple stat any tutor**

Think of the test as μ1>μ2 Is the solution of μ1 on the left, right or both sides of μ2?

**algebra**

slope of line y=(2/5)x+7 is (2/5) Slope of line perpendicular to it is -(1/slope)=-5/2.

**Frenchhhhhhhhhh**

All the cases are direct objects, so you need to replace them by le/la or les (not "des")depending on whether the nouns you are replacing are in singular or plural, and masculine or feminine. There is an extra caution in French is that the pronouns of direct objects ...

**Frenchhhhhhhhhh**

Replace by what?

**Algebra - clarifications required**

y=2x=1 is not an equation of a line. Please clarify the typo.

**Algebra - clarifications required**

1. slope = 15/12 2. slope = -5/4 3. slope = ? (two equal signs, so the sign of the slop could go either way. Please clarify.

**pre calc**

If sin(x)=-3/5 in Q3, then cos(x)=-4/5 (using cos²(x)=1-sin²(x)) Similarly, cos(y)=5/13 in Q1 means sin(y)=12/13 sin(x-y)=sin(x)cos(y)-cos(x)sin(y) =-3/5*5/13 - (-4/5)*12/13 =(-15+48)/65 =33/65

**Math**

Yes, it's correct. 2 gals must be added (and well agitated).

**Math (Probability)**

The size of the sample space of the last throw is 20*20=400. Out of the 400 outcomes, Bret needs those where his throw is 11 or more than Shawn's, namely: (12,1),(13,1),(14,1)...(20,1) (13,2),(14,2)...(20,2) ... (19,8),(20,8) (20,9) There are ∑(i), i=1,9 outcomes. Can ...

**math**

One cup is 240 ml 1 table-spoon is 15 ml. So 1 cup = 16 table-spoons How table-spoons are in 16 gals? This equals how many cups?

**Math**

Certainly, if the father has a foot-length equal to 150% of that of Aaron.

**Physics**

Use the definition of a Coulomb. There are 11 ampères of current 10 minutes = 600 seconds. Can you now figure it out?

**math**

Let E=age of Mr. Edwards. (E+15 + E/3+15) = 86 Solve for E.

**Pre-Calculus**

Draw a right triangle with XY vertical, and a base AX of 200 ft. The angle XAY=25 degrees. Use the definition of tangent(A)=tangent(25°)=XY/AX Solve for XY.

**7th Grade Math**

Volumes are (linear ratio)³ and areas are (linear ratio)²

**probability**

There were 40 outcomes, of which 6 were spinning a 2. Experimental probability = 6/40 = 3/20.

**7th grade math help :)**

You're welcome!

**7th grade math help**

Assuming one must make a single choice in each group, so it is a three-step experiment. choices for group 1 = 2 choices for group 2 = 3 choices for group 3 = 2 Total number of outcomes in the sample space is therefore the product of the choices in each group (step).

**physics**

v0=5.5 m/s v1=0 m/s F=160 N m=80 kg Use Newton's second law, F=ma a=F/m=-2 m/s-2 (deceleration) Use: (v1^2-v0^2)=2aS So S=(v1^2-v0^2)/2a=30.25/4=7.5625 m

**Physics**

F=>M2=>F1=>M1 On the frictionless table, both will have an acceleration a. Draw the free-body-diagrams (FBD) and conclude that M2.a = (F-F1) M1.a = F1 using Newton's second law. Solve for F1 and a. Part (b) can be found in a similar way.

**calculus**

Steve is right. Whenever you transpose a fraction from a book to a single line to post, you need to insert the implicit parentheses. In this case, I believe it is 1000 = 10,000(1 − (5/[5 + e^−0.001x]))

**calculus**

p = 10,000(1 − (5/5 + e^−0.001x)) for p=1000, 1000=10000(1 − (5/5 + e^−0.001x)) 5/(5+e^(-0.001x)=0.9 e^(-0.001x)=5/0.9-5 take log -0.001x = log(5/0.9-5) x=-1000 log(5/0.9-5) =587.8, say 588 (b) can be done in a similar way.

**Math 208**

Let x be the amount he invested at 6%. Then x-1400 is the amount he invested at 5%. Total interest after 1 year x*0.06+(x-1400)*0.05=172 0.11x=172+1400*0.05 0.11x=242 x=2200 Check 2200*0.06+800*0.05=132+40=172 ok.

**programming - C++ or Java?**

The instructions are quite clear as to what to do. I suggest you read through your teacher's notes or instructions and give an attempt. Programming is learned by actually writing and compiling code. Copying or reading alone will not help you solve your next problem. You...

**Physics**

Speed of sound in sea water depends on the temperature and salinity. At 25 degrees and 35 ppt salinity, the speed of sound is approximately 1551 m/s. So divide 19000/1551 to give the time in seconds it takes.

**Math**

Basically you cannot. A bar graph puts different numbers into the same class, and so there is loss of information. If you have a problem in hand, post the data (if they are not too numerous) and we can appreciate better the problem in hand.

**Calculus**

Parentheses are implicit when it is printed in fraction form. If it is printed as a fraction, your post is linearizing it (put on a single line) and it is necessary to insert parentheses around all numerators or denominators which contain more than one term.

**Calculus - clarifications required**

Could you please insert parentheses to clarify the question? 10x-3/5x+6x could mean (10x-3)/(5x+6x) [??] 10x -(3/5x) + 6x [??] [(10x-3)/5x] +6x [??} etc.

**Algebra - clarifications required**

Jamila, please clarify what SR stands for. Is it a monetary unit, or is it an abbreviation for some term?

**calculus**

Find derivative with respect to x: y'(x)=dy/dx=6x-5 Evaluate derivative at x=3: y'(3)=6(3)-5=13

**Algebra**

Using calculus, it would be finding dy/dt and equating to zero to solve for t. Since it is algebra, you could complete squares: y=-4.9(t-7)²+49*4.9 =-4.9(t-7)²+240.1 which means that the maximum height of 240.1 m at t=7.

**math**

You can take the average, namely [(1+2)/8]2 = 3/16 If you want just ANY fraction between, you can add the numberators and denominators: (1+1)/(8+4)=2/12 = 1/6

**Computer Science**

Depending on the complexity of the game, it takes proficiency in the language, which means lots of late nights leaning and practising programming on different projects. In short, you have to like it so that it is not work, but fun.

**please hurry**

It is almost impossible to show the calculations here because the proportional font used here makes it difficult to line up calculations. You can look up an example at the following link: http://www.homeschoolmath.net/teaching/square-root-algorithm.php

**maths-formula**

Sorry mate, this expression does not have rational factors.

**Physics**

Since it is an elastic impact, we can equate energies.

**Probability**

Only question left is how Andrew found a fair 10 sided die. Platonic solids have 4,6,8,12 and 20 sides!

**Probability**

Use a probability tree to find that the overall probability of winning is [∑(i²)/100]/10] for i=1 to 10 =385/1000 which should be simplified to an irreduceable fraction a/b. The sum of a+b is then 277.

**maths**

Subdividing a pizza according to the number of people, getting change after paying for a purchase, finding unit price of items in a grocery store to compare unit cost, checking that the restaurant bill is correct, calculating tip, counting money after a withdrawal, finding the...

**Algebra**

See http://www.jiskha.com/display.cgi?id=1369047938

**Algebra**

See http://www.jiskha.com/display.cgi?id=1369047938

**French-SraJMcGin**

Watch spellings of "Sacré-Coeur", as pointed out by Mme Sra. The proper name seems to be "La Basilique du Sacré Coeur"

Pages: <<Prev | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | **13** | 14 | 15 | 16 | 17 | 18 | 19 | Next>>