Tuesday

October 25, 2016
Total # Posts: 45,282

**Calculus**

see your text for examples, or http://mathinsight.org/parametrized_curve_tangent_line_examples

*September 12, 2016*

**Math**

#1. Just pick any 6 consecutive integers and try it out #2. Consider the numbers x-2, x-1, x, x+1, x+2 #3. Should be clear. Even if you're not sure about some of them, the right one jumps out. #4. any multiple of 2 is even #5. start by noting that 17 is prime #6. trick ...

*September 12, 2016*

**algebra**

solve for what? And of course, it's probably vt, not ut.

*September 12, 2016*

**algebra**

do the division. If the remainder is subtracted, the new remainder will be zero.

*September 12, 2016*

**SS ICY NORTH**

I see someone else (not you?) was asking about Canada icy north google turned up several references for that

*September 12, 2016*

**SS ICY NORTH**

Hmmm. I see a few hits on google, but they relate to different topics. I see your subject is social studies. What kind of ICY NORTH are you referring to? Climate, Rock Band, what?

*September 12, 2016*

**SS ICY NORTH**

google

*September 12, 2016*

**Physics**

46 mi/hr = 20.56 m/s so v = at means t = 20.56/2.35 s work the other similarly or, just consider the ratio of time lengths

*September 12, 2016*

**profit and loss**

do you mean that If he now gets x eggs for rs10 he would get x+6 eggs or the discount lets him get 6 eggs for rs10?

*September 12, 2016*

**Science**

try this https://www.google.com/#q=inductive+vs+deductive is that your final answer?

*September 12, 2016*

**Calculus**

The population in a ring of radius r is density * area, so adding up all the rings you get ∫[0,7] 6∛(3+r^2) * 2πr dr hint: let u = 3+r^2 for the volume, you can use shells: ∫[0,5] 2πrh dx = ∫[0,5] 2πx(5x-x^2) dx discs: ∫[0,25] π...

*September 12, 2016*

**physics**

https://www.google.com/#q=drift+velocity+area+conductor

*September 12, 2016*

**Algebra2**

well, assuming your = means +, 6x+9y=6 6x-10y=44 ...

*September 12, 2016*

**Math**

f(x) = (1/x)^(sinx) = 1/(x^sinx) Let us take the limit as x→0+, since rasning negative numbers to real powers is not well defined. consider limit x→0 g(x)=x^x lng = x lnx = lnx/(1/x) limit ln g(x) as x→0 = (1/x)/(-1/x^2) = -x limit ln(g(x)) = 0 so, limit g(x...

*September 12, 2016*

**Maths Percentage**

1.4 * ate = 70 ate = 50 what do you get for the other parts? If you get stuck, show how far you got. You must have at least some idea where to start, even if it is only defining a variable.

*September 12, 2016*

**precalculus**

ok. It appears to be in QIV, and is a 12-35-37 right triangle. If you draw it correctly, you should be able just to read off the values of the trig functions of that angle.

*September 12, 2016*

**Maths Percentage**

Syed's is 5/4 of Emraan's So, Emraan's is 4/5 of Syed's

*September 12, 2016*

**Math**

no problem. Feel free to stop by any time, but next time you need to ante up some work before we bother betting.

*September 12, 2016*

**Math**

As written, I get none of the above. Show your work, and we can check what's going on. To get -16, the 2nd term must come out to -32, since 16-32 = -16

*September 12, 2016*

**mechanic**

200^2 + 200^2 - 2*200*200cos(π-θ) = 100 the two forces must be very nearly in opposite directions.

*September 12, 2016*

**science**

120g/6mL = 20g/mL

*September 12, 2016*

**Math**

.10*100 + .20*89 + .55*82 + .15*81 ≈ 85

*September 12, 2016*

**Calculus**

well, I get -114.755 so maybe the key wants -114.76 or -114.8 or -115

*September 12, 2016*

**Calculus**

I think you subtracted wrong. Try (f(4)-f(-5))/9 = -114.75 as a quick look at the graph would indicate: http://www.wolframalpha.com/input/?i=3x%5E3-12x%5E2

*September 12, 2016*

**Calculus**

L'Hospital's Rule: (1/(1+x^2) - 1)/(3x^2) = (-x^2/(1+x^2))/(3x^2) = -1/(3(1+x^2)) -> -1/3

*September 12, 2016*

**Math**

if there are 5x girls and 12x boys, then 17x = 5200 Hmmm. 17 does not divide 5200. Now, if there were 5100 students, then x = 300.

*September 12, 2016*

**Maths**

well, 25tanx = 17cosy, so see what you can do with that.

*September 12, 2016*

**Math**

what, no ideas of your own? at all? none?

*September 12, 2016*

**Math**

1: 5.310 5: 101.1 now you try the others. we'll check your results

*September 12, 2016*

**Math**

c = πd love your creative syntax

*September 12, 2016*

**maths**

ok, now what?

*September 12, 2016*

**Math**

a = (17-8)/3 = 3 m/s^2 s = vt + a/2 t^2

*September 12, 2016*

**Math**

Well, just plug in n=101! (101+1)x+(-1+2(101-1)) = 102x + 199

*September 12, 2016*

**math**

(n+1)x + (-1 + 2(n-1))

*September 12, 2016*

**Math**

no clue. no info.

*September 12, 2016*

**algebra**

yes

*September 11, 2016*

**a**

No idea where the u and z came from, but the -8x-3y is ok

*September 11, 2016*

**maths**

here's a nice linear algebra solver: http://www.zweigmedia.com/RealWorld/LPGrapher/lpg.html

*September 11, 2016*

**Math**

use the law of cosines. The included angle is 50°

*September 11, 2016*

**physic**

at time t they will be at the same height, when 17-4.9t^2 = 23.5-7.36t-4.9t^2 use that t to get the height since gravity affects both balls equally, their speed difference is constant.

*September 11, 2016*

**4th grade math**

21,849 + 38,932 ≈ 20,000+40,000

*September 11, 2016*

**Math**

90-105 = ?

*September 11, 2016*

**Precalculus**

xy = 172 x = 2y-8 solve for x and y, and then the diagonal is √(x^2+y^2)

*September 11, 2016*

**Math**

5 1/6 = 30/6 + 1/6 = ?

*September 11, 2016*

**ALGEBRA**

If there are x ml of 20% then the rest (100-x) is 40%. So, add up the acid in the parts; it must equal the acid in the result: .20x + .40(100-x) = .24*100 and that's liters, not leters. When you get your answer, note that 24% is 1/5 of the way from 20 to 40, so 1/5 of the ...

*September 11, 2016*

**Math**

y-x = 20 (x+y)/3 = 40

*September 11, 2016*

**college**

60 rev/min * 2π rad/rev = 120π rad/min the linear speed is just radius * angular speed 120π/min * 15in * 1ft/12in * 1min/60s = (120π*15)/(12*60) ft/s

*September 11, 2016*

**math**

First step: distributive 6x-8 = 8x-11 now what?

*September 11, 2016*

**Math**

Tn must surely be (n+1)x + (-1 + 2(n-1)) = (n+1)x + 2n-3

*September 11, 2016*

**math**

note that S increases by 5 for every +1 change in N.

*September 11, 2016*

**Math**

exactly reversed. How can you possibly add two positive numbers and sometimes get a negative result???

*September 11, 2016*

**Algebra**

y = mx+b 21m+b = 58 43m+b = 42.6 Solve for m and b, and then figure y when x=59. Or, note that 22 minutes of driving covered 15.4 miles. So, after 16 more minutes, he covers (16/22)(15.4) more miles. Subtract that from 42.6

*September 11, 2016*

**Algebra 1 Foundation Concepts rewrite**

6 B,C http://www.virtualnerd.com/algebra-2/equations-inequalities/real-numbers/number-types/natural-and-whole-numbers-definition Surely your text explains all this.

*September 11, 2016*

**Math**

(a) 10(+0.30) = +3.00 That's my work so far. Have any of your own?

*September 11, 2016*

**Math Trigonometry**

use the law of cosines. The included angle is 50°

*September 11, 2016*

**Mathematics**

(b) clearly d=4, since T16-T8 = 8d = 32 Now do (a) and (c) For (c), note that T20-T16 = 4d

*September 11, 2016*

**Math Trigonometry**

actually, if you draw the parallelogram, you will see that you have the wrong diagonal. R^2=22^2+35^2-2*22*35*cos(180-52) If the vectors are u and v, you want |u+v|, not |u-v|

*September 11, 2016*

**Trig**

use the law of cosines. The included angle is 50°

*September 11, 2016*

**Math**

you have a problem balancing your grouping symbols. How did you get 14?

*September 11, 2016*

**Math**

-2+3[6-(1-9)] -2+3[6-(-8)] -2+3[6+8] -2+3[14] -2+42 40

*September 11, 2016*

**Math Domains**

You know that you cannot take the square root of a negative number. That means that you must have x(x-2) >= 0 So, either both factors are negative, or both are positive. Thus, the domain is (-∞0]U[2,∞) You can visualize this by graphing the parabola. It opens ...

*September 11, 2016*

**Math**

Your math is correct, but your choice is not Think of (1/2) as a unit, like books, dollars, etc 9 of them divided by one of them is 9 9/2 km is the goal 1/2 is each trip So, 9 is the number of trips needed to reach the goal: (D)

*September 11, 2016*

**Math**

note that (p-q)^2 = p^2 - 2pq + q^2

*September 11, 2016*

**algebra**

what, reposting after only 3 minutes? impatient much?

*September 11, 2016*

**math**

a little synthetic division shows 4x^2-10x+21 R -41

*September 11, 2016*

**math**

(3rd)^2 = 9 rd^2

*September 11, 2016*

**College Algebra**

by steadily, do you mean it rises by the same amount each year or it rises by the same percent each year ?

*September 11, 2016*

**Algebra**

well, it appears to drop 400 each time. So, what does that tell you?

*September 11, 2016*

**Math**

divide by 2 and you have 3/2 cm : 1m

*September 11, 2016*

**math**

or x40

*September 11, 2016*

**maths**

There sure is a lot of gobbledegook there. If we say that the center lies on the line x = 2t-1 y = 3t+1 Apparently the center of the circle lies on the line y = (3x+5)/2 The circle passes through (-3,-1) So, we need (-3-h)^2 + (-1-(3h+5)/2)^2 = 100 h=3 or -105/13 so, k= 7 or -...

*September 11, 2016*

**Calculus**

I assume you meant to ask: How fast is the shadow moving on the wall, when the distance from the man to the center of the courtyard is 1/2 r Let's set this up in polar coordinates. Let's call the radius a, so we can use r as a function of θ. Set the light at the ...

*September 11, 2016*

**Math**

64.4/20 * 100 cm

*September 11, 2016*

**Algebra**

1/30 + 1/25 = (5/6)/x

*September 11, 2016*

**Math**

sin(kx) has period 2π/k the other requires some numeric or graphical techniques: But you know it will be somewhere near x=25, since |sinx| <= 1 and 25-x=0 at x=25 http://www.wolframalpha.com/input/?i=25+%E2%88%92+x+%E2%88%92+sin(x)

*September 11, 2016*

**Math**

1. What is one period of the function f(x) = 120 sin(120πx). 2. When does f(x) = 25 − x − sin(x) cross the x-axis?

*September 11, 2016*

**Algebra**

Ah, I think you mean f(x) = a * b^x I guess that means a/b^3 = 30 ab^1 = 13 Is that anywhere near what is wanted? If not, can you explain a bit, or give a pointer to examples of this notation?

*September 11, 2016*

**algebra**

If it is a multiple of 9, its digits must add to a multiple of 9. I think you are missing a dash, since it cannot start with 6 and end with 5 and be a palindrome.

*September 11, 2016*

**Exponential Inequalities**

2/5^(5x-1) >= 25/4 8 >= 5^2*5^(5x-1) 8 >= 5^(5x+1) 5x+1 <= log8/log5 x <= (log8/log5 - 1)/5

*September 11, 2016*

**Math**

S: 3n+1 L: 2n

*September 11, 2016*

**maths**

the area consists of six isosceles triangles, each with base = 3.5m Check how to find the apothem of a regular hexagon. If the apothem is a, then the height of each triangle is the slant height of the pyramid: √(1.9^2 + a^2)

*September 11, 2016*

**maths - clarify**

is that √(2 cotx) or (√2)cotx?

*September 11, 2016*

**Mathematics**

12800((1+.15/4)^2 - 1)

*September 11, 2016*

**math**

1+3(n-1) = 3n-2

*September 11, 2016*

**differential equation**

see related questions below

*September 11, 2016*

**Geometry**

consider that the diagonal of the square is the diameter of the circle.

*September 11, 2016*

**Geometry**

see related questions below

*September 11, 2016*

**math**

a quadrant is 1/4 of a circle. I'm sure you can find the area of a whole circle, yes?

*September 10, 2016*

**Math trigo**

is that 660 minutes? If so, 660' = 11° If you meant 660°, then since 660 = 360+300, tan660° = tan300° Now, since 300 = 360-60, tan660° = -tan60°

*September 10, 2016*

**Math**

left 4, up 6

*September 10, 2016*

**Geometry**

since MP bisects <LMN, m<LMP is 1/2 of m<LMN. So, m<LMN = 2(m<LMP) 10x-6 = 2(4x+3) Now find x and m<LMN = 10x-6

*September 10, 2016*

**Math**

it's easy to fin P1(no cubes) or P2(no spheres). P(some of each) = 1 - (P1+P2)

*September 10, 2016*

**Math**

while the tangent line is the limit of the secants lines, that was not the question. It said h > 0. Draw a parabola. The secants are always steeper than the tangents. So, (A)

*September 10, 2016*

**Calculus 1**

h = d/4 = r/2 So, r = 2h v = π/3 r^2h = 4π/3 h^3 dv/dt = 4πh^2 dh/dt Now just plug in your numbers.

*September 10, 2016*

**Physics**

yes, the final velocity is ∆x/∆t = 630km/12.6hr = 50 km/hr So, the acceleration is ∆v/∆t: (50km/hr)/(1/2 hr) = 100km/hr^2 You might want to put that into standard SI units of m/s^2.

*September 10, 2016*

**Pre-Calculus**

5 minutes is 1/12 of an hour. The hand makes one complete circle in an hour So, it moves 1/12 of the whole circumference in 5 minutes. I assume you know how to find the circumference of a circle of radius 3. Note that since there are 2π radians in a whole circle, that is ...

*September 10, 2016*

**8th Grade Pre-Algebra**

starting at the decimal point (or the rightmost digit if there is none), count how many places left you have to move the point till the number is between 1 and 10 (less than 10). Note that 10^0 = 1 108,000,000 = 108,000,000 x 10^0 108,000 x 10^3 108 x 10^6 10.8 x 10^7 1.08 x ...

*September 10, 2016*

**Algebra**

rate of change is how fast y changes when x changes by 1. y = -2x+6 Note that -2 in front of x. That is the slope of the line, or also the rate of change. You can see that adding 1 to x add -2 to y. So, -2 is the rate of change (of y with respect to x). y = -3x+10 slope = -3 ...

*September 10, 2016*

**Alg**

see prior post

*September 10, 2016*