Friday

October 9, 2015
Total # Posts: 31,225

**triginometry**

how about sin 57°29' = h/9 ?
*May 14, 2015*

**Math1210**

let the width be y m and each of the lengths x m so 2x + 2y = 300 x + y = 150 y = 150-x cost = 50(2x+y+ = 50(2x + 150-x) = 50x + 7500 then 50x + 7500 = 12000 50x = 4500 x = 90 y = 150-90 = 60 the field is 60 m by 90 m
*May 14, 2015*

**maths**

any square contains at least a PAIR of equal factors e.g 1600 = 5x5 x 8x8 so ... 103875 = 25x4155 = 25 x 5 x 831 = 25 x 5 x 3 x 277 , and 277 is prime so to make pairs, we need a 5, a 3, and a 277 5(3)(277) = 4155 so if 103875 is multiplied by 4155 the result is a perfect ...
*May 14, 2015*

**geometry**

Your question makes no sense. To me congruent circles would be circles that have the same radius. What do you mean by "one has a lenght of 8ft" Is that supposed to be the circumference ? If the second has a "length" of 4 ft, then it must be smaller, ...
*May 13, 2015*

**Math @Reiny**

This must be re your previous post from above: centre is (2,0) c is from centre to focus or c = 2 2a = 8 a = 4 you should know that for a horizontal ellipse, a^2 = b^2 + c^2 16 = b^2 + 4 b^2 = 12 (x-2)^2 /16 + y^2 /12 = 1
*May 13, 2015*

**math**

let the base be x by x after cut out, base is (x-3) by (x-3) and the height is 3 3(x-6)(x-6) = 243 (x-6)^2 = 81 x-6 = ±9 x = 15 or x is a negative which would make no sense so the base was 15 by 15 inches check: after cutting out 3 inches from each end, the base is 9 by...
*May 13, 2015*

**Algebra 2 Honors**

you did your first 3 questions by using ratios. This is fine as long as you know where to put the numbers. since you appear to understand that direct variation ---> y = kx inverse variation ---> y = k/x perhaps that is the approach you might take at the beginning. 1. It ...
*May 13, 2015*

**Math**

since the change is in only one of the dimensions, the change of the volume must be linear. height was tripled, so the volume is doubled or new volume is 54 in^3 or old volume = 3(l)(w) = 3lw = 27 lw = 9 new volume = 6(l)(w) = 6lw = 6(9) = 54
*May 13, 2015*

**Math**

tomatoes: (1/4)(12) = 3 remainder = 9 pears = (1/3)(9) = 3 remainder = 6 radishes = (1/2) of 6 = 3 leaving 3 for the lettuce so 3 ft^2 of radishes
*May 13, 2015*

**algebra - please help!**

P(1 - (1 + .08/4)^-20)/(.08/4) = 2400 P(1 - 1.02^-20)/.02 = 2400 P = 146.78
*May 13, 2015*

**Math**

correct
*May 13, 2015*

**Math**

Not enough information for 1. all we know is that the centre is (2,0) and c = 2 (x-2)^2 /a^2 + y^2 / b^2 = 1 where a^2 = b^2 + 4 2. centre is (0,1) , a = 2 , c = 3 in a hyperbola: a^2 + b^2 = c^2 4 + b^2 = 9 b^2 = 5 x^2 /4 - (y-1)^2 /5 = 1
*May 13, 2015*

**Math Check**

a^2 = 3 , b^2 = 4 a = √3 , b = 2 so you have a vertical major axis, thus the x's must be the same , eliminating A and C y^2 + √3 ^2 = 2^2 y^2 = 4 - 3 = 1 y = ± 1 so the centre is (2,2) moving one up and one down from there gives us (2,3) and (2,1) e = c/...
*May 13, 2015*

**math help please**

no on both counts x^9/x^2 = x^9 ÷ x^2 to divide powers with the same base, keep the base and subtract the exponents, so x^7 #2, h^9
*May 13, 2015*

**Please help**

Yes, the combination of alliances and counter-alliances as well as the national pride, ignorance and arrogance of the leaders of Germany, Britain, France, Austria-Hungary, and Russia were the primary cause of World War I Just finished an excellent book: The War That Ended ...
*May 13, 2015*

**Math**

-tanØ = √3 tanØ = -√3 , so Ø is in II or IV first primary answer = 120° 2nd primary answer = 300° , notice the difference between them is 180° and the tangent curve has a period of 180° so we can get away with a single general ...
*May 13, 2015*

**Math Ms.Sue???**

You will need the slant height s , the hypotenuse s^2 = 4^2 + 6^2 = √52 surface area = πrs + (πr^2) , using the formula on Ms Sue's page = 4√52π + 16π You didn't state if the circular base is to be included, so .... your choice.
*May 13, 2015*

**math help please**

The area of a rectangle = length x width = 8x(7x+1) expand to see which matches btw, it is a rectangle not an angel
*May 13, 2015*

**Geometry/Math**

volume of 1st = π(36)(12) = 432π volume of 2nd = π(64)h 64π h = 432π h = 432π/(64π) = 27/4
*May 13, 2015*

**Math**

Your answers are correct. Be careful with brackets on a site such as this. e.g. in #1 you will have to type it as (x+5)/(x^2 + 6x + 5) and your answer is 1/(x+1), x ≠ -1 As to the x ≠ ?? the concern is the denominator, e.g. in #1, we have x+1 as a denominator. What...
*May 13, 2015*

**MATH I NEED HELP**

let the number of deer be x (16/800)x = 120 (1/5)x = 120 x = 5(120) = 6000 or use a ratio: 16/800 = 120/x 1/5 = 120/x x = 5(120) x = 6000
*May 13, 2015*

**Geometry**

I will assume you meant (20+x)/x = 6/5 (those brackets are essential) now cross-multiply ... 6x = 100 + 5x x = 100
*May 13, 2015*

**Math**

3 consecutive questions dealing with varied topics. Are you expecting us to do an assignment for you? What are your difficulties, and what steps have you to show me ?
*May 13, 2015*

**Math**

I suggest you graph on the same grid 1. y = x+1 , which is a very simple straight line 2. y = cosx , which is the basic standard cosine curve and see what happens
*May 13, 2015*

**math**

This is the same style of question I just answered for you in the previous post. Just follow the same steps.
*May 13, 2015*

**math**

Volume of well = π r^2 h = π(3.5)^2 (40) = 490π cubic metres let the height of the plateform be h 28(22)h = 490π h = 490π/616 = 35π/44 metres or appr 2.5 m
*May 13, 2015*

**Math**

general term = term(r+1) =C(10,r) (x^2)^(10-r) (1/x)^r = C(10,r) x^(20 - 2r) x^(-r) = C(10,r) x^(20 -3r) so 20 -3r = 11 -3r = -9 r = 3 C(10,3) = 120 the term containing x^11 is 120x^11 and it is the 4th term confirmation by Wolfram: http://www.wolframalpha.com/input/?i=expand...
*May 13, 2015*

**Math**

I answered this http://www.jiskha.com/display.cgi?id=1431486984
*May 12, 2015*

**geometry**

it is called the hypotenuse (you give no values or variables, so who knows ?)
*May 12, 2015*

**Math**

sinØ = -2/13 and we are told Ø is in III so y = -2, r = 13 x^2 + y^2 = r^2 x^2 + 4 = 169 x= ±√165 , but in III x = -√165 cosØ = -√165/13 cos 2Ø = cos^2 Ø - sin^2 Ø = 165/169 - 4/169 = 161/169
*May 12, 2015*

**Geomerty**

The mystery remains unsolved with only one bit of information about the triangle.
*May 12, 2015*

**Math**

Expand it That would be your other version
*May 12, 2015*

**Math**

Let the positive square number be x 2x^2 + 3x = 14 solve for x: 2x^2 + 3x - 14 = 0 hint: it factors, remember to reject the negative answer.
*May 12, 2015*

**Pre-Algebra**

1. how did you get 24 ? f(x) = x^2 - 3x + 2 f(-2) = (-2)^2 - 3(-2) + 2 = 4 + 6 + 2 = 12 2. E = 12m 3. correct 4. y = 1.15 + .95(x-1)
*May 12, 2015*

**math**

If you plot the points you will get a rectangle of length 6 and height of 4 so the perimeter is 12 + 8 or 20 units take over
*May 12, 2015*

**Math**

recall the difference of squares: a^2 - b^2 = (a+b)(a-b) this has the same pattern (x+y)^2-(x-y)^2 = (x+y + x-y)(x+y - (x-y)) = 2x(2y) = 4xy or you could just expand the original ... (x+y)^2-(x-y)^2 = x^2 + 2xy + y^2 - (x^2 - 2xy + y^2) = 4xy
*May 12, 2015*

**Trig Identities**

good start LS = sinx/cosx + 1/cosx = (sinx + 1)/cosx multiply top and bottom by (sinx - 1)/(sinx - 1) = (sinx + 1)/cosx * (sinx - 1)/(sinx - 1) = (sin^2 x - 1)/(cosx(sinx - 1)) = cos^2 x/(cosx(sinx - 1)) = cosx/(sinx - 1) = RS
*May 12, 2015*

**math**

I will assume you mean: the sum of the first five terms is 783/2 5th term is 60---> ar^4 = 60 the sum of the first five terms is 783/2 ---> a(r^5 - 1)/(r-1) = 783/2 divide the 2nd by the 1st a(r^5 - 1)/( (r-1)ar^4) = (783/2)÷60 (r^5 - 1)/(r^5 - r^4) = 261/40 261r^...
*May 12, 2015*

**algebra**

1 <---> 11 3 numbers greater than 9 2 numbers less than 3 Prob( as stated) = (3/11)(2/11) = 6/121
*May 12, 2015*

**Algebra II**

again, I think they mean -5(x + 10)^2=390,625 (why would you put a multiplier in front and behind a binomial ?) (x+10)^2 = -78125 which is not possible since the square of anything is positive. So, no solution.
*May 12, 2015*

**Algebra ii**

I have a feeling judging by the numbers that he meant: (x-16)^(4/3) = 81 x - 16 = 81^(3/4) x - 16 = 27 x = 43
*May 12, 2015*

**Pre Calculas**

x^2 = 3^2 + 7^2 x = ....
*May 12, 2015*

**Functions**

given : log2 7 = 2.807 log2 7 = log2 (2x7) = log2 2 + log2 7 = 1 + 2.807 = 3.807
*May 12, 2015*

**Math**

looks like 8 c^6 d^3 to me
*May 12, 2015*

**maths**

.... 1.5 times the sum of the three angle of a triangle ---> 1.5(180) or 270° so sum of 3 angles + x = 360° 270+x=360 x = 90°
*May 12, 2015*

**Probability**

prob(blue) = prob(brown) = 1/2 a) so prob(first child brown) = 1/2 since these prob's are independent, that is, just because the first child has brown eyes, does not mean the second is more likely to have blue eyes so prob(2nd have blue) = 1/2
*May 12, 2015*

**math**

for sequential integer values of n, number = -9n + 17 e.g. n = 3, number = -9(3)+17 =-10
*May 12, 2015*

**ms sue! Algebra help**

You should be familiar with the cosine curve Look at the bottom of this page: http://www.regentsprep.org/regents/math/algtrig/att7/othergraphs.htm The cosine curve runs from -1 to +1. cos(0) = 1 cos(60°) = 1/2 cos(90) = 0 cos(120) = -1/2 etc since secx = 1/cosx at any ...
*May 12, 2015*

**Math**

6. f(-2) = (-2)^2 - 3(-2) + 2 = .... 7. no choices shown "now" the lawn ? You typed it twice, so clearly no typo.
*May 12, 2015*

**Math**

My ruler is marked in inches not months. On mine the 2 inch marks would be 2, 4, 6, 8, ... and 5 1/4 = 5.25, so where do you think it will fall ?
*May 12, 2015*

**Maths**

y = 2x - 4 is not an exponential function, it is linear and its graph is a straight line
*May 12, 2015*

**Math (Riemann Sums)**

I will assume your n = 4 implies you want midpoints as follows 0 -->18 = 9 18 --> 19 = 18.5 19 --> 24 = 21.5 24 --> 12 = 18 so I would have 30(9+18.5+21.5+18) = 2010
*May 12, 2015*

**Math probability**

10 pieces of fruit, 4 apples and 2 apric. prob(apple, then appricot) = (4/10)(2/10) = 8/100 = 2/25 how did you get 3/5 ?
*May 12, 2015*

**Math**

volume of a rectangular prism (a box) = lwh if it is a pyramid with the same base and height V = (1/3)(lwh)
*May 12, 2015*

**geometry**

vertex angle ---- x each of the two equal angles ---- 2x x+2x+2x=180 x = 36°
*May 12, 2015*

**Math**

your statement -2 < π < 2 makes no sense, it simply becomes a false statement: -2 < 3.14.. < 2 I will assume you meant: -2π < Ø < 2π the obvious one: (3,-4π/3) 2 more: (3,-π/3) , (3,5π/6)
*May 12, 2015*

**Geometry**

so your two points are A(a,0) and B(b,0) from A to B = √( (b-a)^2 + 0^2) from B to A = √( (a-b)^2 + 0^2) but (a-b)^2 = (b-a)^2 , (when you square a number the result is positive) e.g. 5^2 = (-5)^2 so the two results are the same
*May 12, 2015*

**Trig identities**

LS = sinx/(1 - cos(-x)) first of all cos(-x) = cosx, so let's change that = sinx/(1 - cosx) now multiply top and bottom by (1+cosx)/(1+cos), thus changing the appearance, but not its value = sinx/(1-cosx) * (1+cosx)/(1+cos) = sinx(1+cosx)/(1 - cos^2 x) = (sinx + sinxcosx)/...
*May 12, 2015*

**Math**

height/50 = tan48° take over
*May 12, 2015*

**Math**

I am not a big fan of double negative-type questions. Perhaps if we change it to: Which is true about the above table? A: It shows a non-linear function. B: The variable x does not increase by 1 each time. C: The rate of change is constant. D: The variable y increases by a the...
*May 12, 2015*

**math**

Since we can't see your diagram, you will have to describe the situation in more detail such as , how far is the spray gun from the wall of the house.
*May 12, 2015*

**algebra**

any horizontal line has equation y = c , where c is the y element of your given point so y = -3 or, the long way: slope of a horizontal line is 0 , then y = 0x + b plug in the given point(5,-3) -3 = 0(5) + b b = -3 y = 0x - 3 y = -3
*May 12, 2015*

**Algebra**

f(x) = 3x - 1 f(0) = 3(0) - 1 = -1 f(3) = 3(3) - 1 = 8 f(z) = 3z - 1
*May 12, 2015*

**Math**

2(x+2)+4x-10x use distribution for the first part = 2x + 4 + 4x - 10x now combine like terms = -4x + 4
*May 12, 2015*

**math**

(2^2)(2^8) = 2^10 so B is the correct answer
*May 12, 2015*

**No - math help please**

It asked for the coefficient of x, which is -7 What you gave is the coefficient of x^2 the correct answer is D
*May 12, 2015*

**Math**

btw, I have a typo, the equation should have said: ax + by + c = 0
*May 11, 2015*

**Math**

Little tricks that can come in handy ... For a linear equation ax^2 + bx + c = 0 the slope is -a/b so the slope of the given line is -3/-2 = 3/2 thus the slope of the new line must be -2/3 But your choice of D has a slope of 3/2, so it can't be D so write the given choices...
*May 11, 2015*

**math**

C) So in effect, the radius of one revolution is 42 cm, and one rotation is 84pi. Multiply 84pi by the number of rotations
*May 11, 2015*

**math**

use the property: ln(e^x) = x 2 = 1 e^(kt) ln 2 = kt t = ln2/k , replace k with the given value
*May 11, 2015*

**maths**

a = 1 , r = -4 you are showing 6 terms, so sum(6) = a(r^6 - 1)/(r-1) = 1((-4)^6 - 1)/(-4-1) = 4095/-5 = -819
*May 11, 2015*

**Pre-calculus ( Absolute value)**

you might plug in x = 5, but x=5 does not satisfy the equation, so it is not a solution. So what if both sides are positive. We know by definition that x-1 > 0 or x>= 1 7+3x = x-1 or -7-3x = x-1 2x = -8 or -4x = 6 x = -4 or x = -3/2 subbing either one of these does not ...
*May 10, 2015*

**math**

... at a rate of 5 inches/hr sounds like a linear rate of change. I will assume that the radius is changing at that rate V = (4/3)pi r^3 dV/dt = 4pi r^2 dr/dt dV/dt = 4pi(100)(5) = 2000pi cubic inches/hr
*May 10, 2015*

**maths**

= 2sqrt(5) - sqrt(5) + 3sqrt(5) = 4sqrt(5)
*May 10, 2015*

**Trigonometry**

RS = (1/2)(cosacosb + sinasinb - (cosacosb - sinasinb) = (1/2)(2sinasinb) = sinasinb = LS
*May 10, 2015*

**Probability**

the second differences are a constant so the relationship is quadratic. the the equation be y = ax^2 + bx + c when x = 1 a+b+c = 20 when x=2 4a+2b+c = 17 when x = 3 9a+3b+c = 13 subtract 1str from 2nd 3a+b=-3 subtract 2nd from 3rd 5a + b = -4 now subtract those last two: 2a...
*May 10, 2015*

**Maths**

the angle between the two directions is 162-25 or 137 Use the cosine law, let the distance between them be d d^2 = 10^2 + 6^2 - 2(10)(6)cos137 = ...
*May 10, 2015*

**Linear Functions**

sketch somethink like y = 2x + 3 (m>0, b>0 ) and see what you get
*May 9, 2015*

**Linear Functions**

e = .04s + 200 see which of your choices match that
*May 9, 2015*

**Math**

(I don't have my calculator with me, so I will describe the method) - find the length of the diagonal of the base using Pythagoras - take half of that length (the midpoint of the base) - use tan^-1 (147/half-length of diagonal)
*May 9, 2015*

**college precalculus I still dont get it**

To be an arithmetic sequence, the difference between any term and its previous term is a constant. e.g. 3, 5, 7, 9 , ... the common difference is 2 To be geometric, if you divide any term by its previous term you will get a common ratio, e.g. 3, 12, 48, ... 12/3 = 4, 48/12 = 4...
*May 9, 2015*

**math**

a) exclude the case where none are cracked Prob(none are cracked) = C(30,0)(.05)^0 (.95)^30 = .... b) follow the above pattern to get Prob(none) + prob(one broken) + prob(two broken) = ..... + C(30,1) (.05)^1 (.95)^29 + .... = ....
*May 9, 2015*

**algebra**

go with Steve, I messed up, right side is .60(20)
*May 9, 2015*

**algebra**

amount of 40% stuff --- x L amount of 85% stuff --- 20-x L .4x + .85(20-x) = .60x
*May 9, 2015*

**Calculus(URGENT PLS!!!)**

how about -e^cosx + c (differentiate it to test my answer)
*May 8, 2015*

**Calculus - Derivative**

2x + r(y)^(-1/2) dy/dx = x dy/dx + y dy/dx (r(y)^(-1/2) - x) = y - 2x dy/dx = (y - 2x)/(r(y)^(-1/2) )
*May 8, 2015*

**Math - Polynomials**

1. The way you typed it should give us 15g + 10k 2. D 3. B Hope you weren't just guessing
*May 8, 2015*

**maths**

the difference between 17^2 and 13^2 is 120. the next perfect square is 121 So we have to add 1
*May 8, 2015*

**7th grade math (probability)**

1-3 are correct #4. you should have divided 4 by 1/6 to get 24 "3" was the event, it happened 4 times, so 4 is the important number last one , I did not check the actual entries, but there are 24 of them
*May 8, 2015*

**Calculus**

here is a picture of what we are doing http://www.wolframalpha.com/input/?i=plot+y%3D+x%5E%281%2F3%29+%2C+y+%3D+x%2C+y+%3D+1 clearly y = x and y = x^(1/3) intersect at (0,0) and (1,1) so outer radius = R = x-1 -->R^2 = x^2-2x+1 inner radius = r = x^(1/3) - 1) --> r^2 = x...
*May 7, 2015*

**Calculus**

V = π∫(y^2) dx from a to b = π∫x^4 dx from 0 to 3 = π[x^5/5] from 0 to 3 = π(243/5 - 0) = 243π/5 cubic units
*May 7, 2015*

**maths**

I see a common factor of 10^7 (5x10^7)+(2.3x10^7) = 10^7(5 + 2.3) = 7.3 x 10^7 your answer should have said 73 x 10^6 In general a number in scientific notation should be a number between 1 and 9 multiplied by a power of 10 so 73 x 10^6, although correct in its value, is not ...
*May 7, 2015*

**Math Please Check My Answer**

From you data it looks like you made 69 choices, thus prob(pink) = 36/69 = 12/23 prob(brown) = 33/69 = 11/23 comparing: theoretical prob(pink) = .5125.. experimental prob(pink) = .5217 not bad
*May 7, 2015*

**Math**

let the base be x by x cm let the height be y xm Volume = (1/3) r^2 h = 216 r^2 h = 648 h = 648/r^2 pick any r, let's say r = 10, then h = 648/100 = 6.48 cm pick x = 12 cm, then h = 648/144 = 4.5 cm As you can see, there is not enough information. as it stands the ...
*May 7, 2015*

**XD**

Suppose it took Alice 4 hrs, when she finished Alice went at 6 km/h Becky went 16 km at 4 km/h Caitlin went 12 km at 3 km/h So for Becky to finish her remaining 8 km would take an extra 2 hrs, but in 2 hrs Caitlin only went 6 more km of her remaining 12 km, so she still has 6 ...
*May 6, 2015*

**XD**

So the total water they have is 2 + 1 3/4 gallons = 15/4 gallons or 3.75 gallons So in effect 3.75 gallons cost $2.00 1 gallon would cost 2/3.75 = .53... so James should receive 2(.5333...) or $1.07
*May 6, 2015*

**Calculus**

did you find their points of intersection? x^2 - 2x = x+4 x^2 - 3x - 4= 0 (x-4)(x+1) = 0 x = -1 or x = 4 effective height of region = x+4 - (x^2 - 2x)= 3x + 4 - x^2 area = [integral] (3x + 4 - x^2) dx from -1 to 4 = [(3/2)x^2 + 4x - (1/3)x^3] from -1 to 4 I will leave the ...
*May 6, 2015*

**Pre-Calculus**

1-|200+||-2|(-5)^3|| 1-|200+||-2|-125|| = 1-|200+||-2(125)| = 1-|200+||-250| = 1 - |200 + 250| = 1 - 450 = -449 I think your |'s are confusing
*May 6, 2015*

**algebra--1 question**

This is called the factor theorem. If the division by some binomial leaves a remainder of zero, then that binomial is a factor the same is true for numbers. e.g. 12÷3 = 4 with Remainder of 0 so 3 is a factor of 12 12÷5 = 2 with remainder of 2, so 5 is NOT a ...
*May 6, 2015*

**Calc**

How do you expect us to know what "table of integrals" you are using ? It is up to you to find the pattern of the given question in your tables.
*May 6, 2015*