Saturday

February 6, 2016
Total # Posts: 37,412

**Math**

We have the point (15,450) and a slope of 4. So, using the point-slope form of the line, we choose (b)
*December 7, 2015*

**Math**

If the shortest side is x and the middle length is y, then x + y + 2x = 19 But 2x is also x+y-3, so y=x+3, and x + x+3 + 2x = 19 x = 4 and the sides are 4,7,8
*December 7, 2015*

**physics**

since work = force * distance, which is greater fd or (2f)(3d) ??
*December 7, 2015*

**computer**

rats. The above loop will include the terminating 999 in the sum. It is a simple change to stop before including it.
*December 7, 2015*

**computer**

as the numbers are accepted, keep track of the smallest. That way there is no need to do a sort later on. read least sum=least val=least WHILE val ne 999 DO read val sum += val least = val if val < least DONE print least,sum Of course, an...
*December 7, 2015*

**Math trigonometry**

Looks good to me.
*December 7, 2015*

**math**

34m+14 = 30m+22
*December 7, 2015*

**Maths**

(2sin+1)/cos = 4cos 2sin+1 = 4cos^2 2sin+1 = 4 - 4sin^2 4sin^2 + 2sin - 3 = 0 Now just solve the quadratic for sin x, and you can then get x.
*December 7, 2015*

**Math**

V = 1/3 Bh If the base has side x, then we see that h=x-2, so 1/3 x^2(x-2) = 25 You can solve the cubic, but it's easier just to note that 5*5*3 = 75
*December 7, 2015*

**Math**

all you really need is the $85 price. A 15% discount gives $72.25 No mention is made of adjusting for profit or costs.
*December 7, 2015*

**Calculus**

if u = e^x you have du = e^x dx ∫√(1+u^2)/u du Now you can use a trig substitution to get around that mess.
*December 6, 2015*

**Calculus**

A more general solution is found below; you can plug in your numbers. http://www.freemathhelp.com/forum/threads/70982-surface-integrals-spherical-cap
*December 6, 2015*

**Calculus**

the cone intersects the sphere where x^2+y^2+(x^2+y^2) = 81 x^2+y^2 = 81/2 that is a circle of radius 9/√2 in the plane z=9/√2 That means the spherical cap has a height of 9(1-1/√2). There are many sites which can give you the formula for that. As for the ...
*December 6, 2015*

**Applied Calc**

everything is just perfect. -1/5 is just a number. Since du = -5x^4 dx, the x^4 dx in the integrand becomes -1/5 du Now just do the integral, and you have -1/5 ln(u)+C
*December 6, 2015*

**Math**

72.25 is what I get.
*December 6, 2015*

**gk**

how can more than all of the students do anything?
*December 6, 2015*

**gk**

1/4 * 1/2 * 2/3 = 1/12
*December 6, 2015*

**trigonometry**

6m * 50 * pi/180 = ?
*December 6, 2015*

**Algebra**

(21^2 + 9^2) = 22.847 But your screen has diagonal of 65. So, just multiply 9 and 21 by 65/22.847
*December 6, 2015*

**calculus**

A satellite is free falling from a distance "d" of the surface of the moon with radius "r", with zero initial velocity. At what rate does the area of the portion of the moon visible to the satellite decrease at a time "t" after the free fall ...
*December 5, 2015*

**Math**

avg speed = (total distance)/(total time) (3*45 + 5*55)/(3+5)
*December 5, 2015*

**math**

nope - direct variation direct: y=kx inverse: xy=k
*December 5, 2015*

**y**

a = Δv/Δt = (-18m/s) / (4.2s) = -4.86 m/s^2
*December 5, 2015*

**Math(analytic geometry)**

At a point (h,4√h) the parabola has slope 2/√h At a point (k,√(8-k^2)) the circle has slope -k/√(8-k^2) (Assume top branch of both curves.) We want the two slopes to be the same, and we want the slope to be ∆y/∆x, so 2/√h = -k/√(...
*December 4, 2015*

**Algebra**

low coefficient means the data do not cluster close to the line. So, not much confidence.
*December 4, 2015*

**Algebra**

numerator must be 1,2,3,4,6,12 denominator must be in 1,2,3,6 + or - also possible look for the easy ones first. I usually eschew fractions, so some trial and error produced 6x^3+13x^2-41x+12 = (x+4)(6x^2-11x+3) Now you can solve the quadratic by factoring or formula.
*December 4, 2015*

**Algebra**

What's wrong with using || symbols? Your keyboard surely has them. #1 ok #2 C |x+3| has x-intercept at -3, but y-intercept is +3.
*December 4, 2015*

**Algebra 2**

this one will not factor into rational roots 9r^2-5r-10 = 0 9r^2-5r = 10 (3r-5/6)^2 = 10 + (5/6)^2 = 385/36 3r - 5/6 = ±√385/6 3r = (5±√385)/6 r = (5±√385)/18
*December 4, 2015*

**math pleaz help quick**

((6.6×10^17)−(9.2×10^14))/(4×10^16) (6600x10^14 - 9.2x10^14)/(4x10^16) (6590.8x10^14)/(4x10^16) 1647.7x10^-2 16.477
*December 4, 2015*

**Trigonometry**

p: lbs of peanuts a: lbs of almonds c: lbs of cashews work with the weights: p+a+c = 140 p = 2a now, work with the values: 3p+4a+8c = 6*140 Now go for it
*December 4, 2015*

**math help azap**

as written, none of them. 17^5÷(17^6)(17^−3)/17^−2 = 1/17^2 17^5÷((17^6)(17^−3)/17^−2) = 1 so, (a) or (e) Put in some other parentheses and you might get other answers.
*December 4, 2015*

**Algebra 2**

well, x^2+2x-8 = (x+4)(x-2) that help?
*December 4, 2015*

**Geometry**

|MA| + |AT| + ... That is, the sum of the lengths of all the sides. But there's an easier formula, since MATH is a parallelogram...
*December 4, 2015*

**algebra**

The cost (c) for (m) minutes is: c = $25.00 + .45m If you think on it a minute, you'll see why this is so.
*December 4, 2015*

**math**

no, y = mx+b has slope m, and y-intercept at y=b You have it backwards. To find a point on the line, pick any value for x, and then find the corresponding value of y. Clearly the easiest value to try is x=0.
*December 3, 2015*

**pre-cal**

clearly that would be 3/8 of the area of the entire circle. I'm sure you know how to find the area of a circle... On the other hand, 3 consecutive seats subtend only two angles, so the area should be 2/8 of the circle, no?
*December 3, 2015*

**pre-cal**

clearly, that would be 20π/8
*December 3, 2015*

**Math**

the co- in the trig functions means co-mplementary angle. cos(x) = sin(90-x) cot(x) = tan(90-x) csc(x) = sec(90-x) #2 true. review the dot product. #3 eh? a vector and a scalar? #4 2*4 + 3*3 if * means dot product #5 <2+4,6+5> for the last one, use the law of sines to ...
*December 3, 2015*

**MATH**

solve what? replace x with whatever you want. So, f(t) = 6t-2
*December 3, 2015*

**Geomertry**

holy smoke! Where to start? The angles on a spherical triangle sum to more than 180, vs 180 in the plane. pick up any text on spherical trig and you can easily list a dozen things right off the bat.
*December 3, 2015*

**Math**

The enlarged rectangle has a new strip of 1/8 inch wide, meaning it is 5 inches long. If x grows by 1 inch (8 times as much), the area will also grow by 8 times as much, or 5 in^2. This assumes that y does not change in all the manipulations.
*December 3, 2015*

**Math**

not tricky at all, if you take the time to draw a diagram. Label the 4 base corners ABCD and the vertex P. Drop an altitude to the center of the pryamid's base, point Q. Draw a perpendicular line from Q to the center of one of the base sides. It meets at point R. Then, ...
*December 3, 2015*

**Math**

The above is gibberish. Why not post the question as it was given to you? The closest thing I can think of to your posting is Hora aderat briligi. Nunc et Slythia Tova Plurima gyrabant gymbolitare vabo; Et Borogovorum mimzebant undique formae, Momiferique omnes exgrabure Rathi.
*December 3, 2015*

**Mathematics**

assuming x-1 > 0, 4x+3 <= 2x-2 x <= -5/2 But we assumed x>1, so no joy there. If x-1 < 0, or x < 1, 4x+3 >= 2x-2 x >= -5/2 So, f(x) <=2 on the interval [-5/2,1) See this at http://www.wolframalpha.com/input/?i=%284x%2B3%29%2F%28x-1%29
*December 3, 2015*

**Math**

it will be 7/2 as big, since all the numbers to be added are 7/2 as big.
*December 3, 2015*

**Math!**

assuming the same f, f(t) = 6t-2 f(2) = 6*2-2 f(-3) = 6(-3)-2 and so on I am confused as to just what your question is. What's to solve?
*December 3, 2015*

**PreCalculas check**

as a quick check, go to wolframalpha.com and type in parabola 8x^2-20x-61/60 It will graph it and describe its properties. Same for the ellipse. As for #1, you must see that it cannot be a parabola. Not with both x^2 and y^2.
*December 3, 2015*

**Pre calculus**

yes - all polynomials have that domain. They are defined for any real number.
*December 3, 2015*

**Pre calculus**

D looks good to me.
*December 3, 2015*

**Pre calculus**

you know that √n must have n >= 0 SO, you need (6-x) >= 0 Now what do you think?
*December 3, 2015*

**Maths**

today
*December 3, 2015*

**math 2 questions plz help asap**

why do you keep guessing instead of thinking??? The front porch is a lot longer than a pencil. NY-CA is many many miles - clear across the country. I see a rough road ahead for you.
*December 3, 2015*

**math 2 questions plz help asap**

do you have any idea of the relative sizes of inches, feet, miles, etc.? Surely you cannot think a pencil is 12 feet long. That is over twice as tall as you are! #2 is correct. You must have some idea about #1, if you know what an inch is.
*December 3, 2015*

**maths: Lowest common multiple**

what is the smallest number which is a multiple of both 8 and 12? 8 = 2*2*2 12 = 2*2*3 so, an multiple of 8 must have 2 as a factor at least 3 times. Similarly, multiples of 12 have at least two 2's and one 3. So, pick the highest power of all the prime factors of each ...
*December 3, 2015*

**Math**

(a+4d)/(a+9d) = 1/2 a+11d = 36 Now you can find a and d.
*December 3, 2015*

**Maths urgent**

√2 + sin = cos cos - sin = √2 cos^2 - 2sin*cos + sin^2 = 2 -2sin*cos = 1 sin(2x) = -1/2 I guess you can take it from there, right? Watch out for spurious solutions (where cos-sin = -√2)
*December 3, 2015*

**math**

google is your friend. So is your textbook.
*December 3, 2015*

**PreCalculas**

#1. vertices indicate you have a vertical axis of symmetry. So, since the foci are evenly spaced from (0,0), y^2/a^2 - x^2/b^2 = 1 The vertices are at y = ±6, so y^2/36 - x^2/b^2 = 1 The asymptotes are y = ±(b/a)x, so b/a = 3/4, or b=8 see the info at http://www....
*December 3, 2015*

**math**

3cos35cosx-3sin35sinX = 3cos(x+35) So, now you have 3cos(x+35)-cosx = 0 Hmmm. not much help. So, back to basics. 6cosx+3cos35cosx-3sin35sinX=7cosx 3sin35 sinx = (1-3cos35) cosx Let c = (1-3cos35)/(3sin35) = -0.847 and you have sinx = c cosx sin^2x = c^2 cos^2c 1-cos^2x = c^2 ...
*December 3, 2015*

**Maths**

Looks good to me.
*December 3, 2015*

**Math**

no idea. It's just a ball; 5 inches or so? Google it to find the official dimensions of a tetherball. However, the circle has a radius of 6 ft.
*December 3, 2015*

**Math**

x + 2x-4 = 180
*December 3, 2015*

**Maths**

I see you have the sum of squares of 3 numbers. I hope that is what you intended.
*December 3, 2015*

**Pre-Calculus**

If you label the 4 points A,B,C,D then it is easy to find the lengths of the 4 sides. Now, the length of AC is 551. Now you have two triangles, and you know all the sides, so you can use Heron's formula to get the areas.
*December 3, 2015*

**Algebra**

#1. n/3 - 8 = -13 #2. ok #3. ok 1/4 = x/3 x = 3/4
*December 2, 2015*

**Math**

L = T+6 F = 2(L+T) F = 32 2(L+T) = 32 2(L+L-6) = 32 2L-6=16 L=11
*December 2, 2015*

**calculus**

Do you have the radius of the moon? Do you have the formula for the distance of the horizon from a height h? Do you have the gravitational acceleration g for the moon?
*December 2, 2015*

**Calc 3**

1st note that e^(2t)+4+4e^(-2t) = (e^t + 2e^-t)^2
*December 2, 2015*

**precalculus**

xy = 800 p = 2x+3y = 2x + 2400/x Now just find x for minimum p. This assumes two rectangular areas sharing a common fence of length y.
*December 2, 2015*

**Math**

yes.
*December 2, 2015*

**Math**

1B no. 36 ≠ 24*3 2D ok
*December 2, 2015*

**College algebra**

If Matt takes x hours, then Jena takes 3x 1/x + 1/3x = 1/9
*December 2, 2015*

**Math**

(110kg * 9.8m/s^2 * 0.3m)/(10s) = 32.3W
*December 2, 2015*

**calculus**

There are any number of calculators online to help you confirm your solution. One is here: http://www.emathhelp.net/calculators/calculus-2/trapezoidal-rule-calculator/
*December 2, 2015*

**5th math**

helps build strong bodies 12 ways!
*December 2, 2015*

**math**

12*10^6
*December 2, 2015*

**functions-math**

f(x) = 3250*(1/2)^(x/4)
*December 2, 2015*

**Algebra**

just collect like terms (same power) (-7y^2-4y+6) = (7y^2-4y-4)-(2y^2-2y-6) -7y^2-4y+6 = 7y^2-4y-4-2y^2+2y+6 -7y^2-4y+6 = 5y^2-2y+2 -12y^2-2y+4 = 0 Not sure what the equal sign is doing there. Simplifying an expression is not the same as solving an equation.
*December 2, 2015*

**Precalculus**

doesn't matter - they are the same. Use whichever one is easier for you to remember.
*December 2, 2015*

**Math**

5*5.75 + 2*7.00 = 42.75
*December 2, 2015*

**precalc**

#1 ambiguous #2 log(x(x-1)) = log 6 x(x-1) = 6 x = 3 #3 assuming base 4 throughout, log25-logx+log3-log7 = 1/2 log(75/7x) = 1/2 75/7x = 4^(1/2) = 2 14x = 75 x = 75/14 Unusual answer. I suspect a typo.
*December 2, 2015*

**Pre Calc**

as you know, all exponential functions y=e^x have y=0 as the horizontal asymptote. So, this is just shifted up by 3.
*December 2, 2015*

**Algebra**

If Stan has x, then Cory has 2x+24 add them up to get 150
*December 2, 2015*

**Math**

(b) has slope -5/-3 so nope. Take a look at (a)
*December 2, 2015*

**Math**

slope is change in y ----------------- change in x Moving from (-2,5) to (1,4) y changes by -1 x changes by 3 So, now you can get the slope. Hard to believe this was not clearly explained and demonstrated in your text. Or heck, remember that google is your friend. No need to ...
*December 2, 2015*

**Algebra 2**

since the sum of logs is the log of the product, you have log((a+2)(a-2)) = log(a^2-4) Here the base is 5, but the rule holds for any base.
*December 2, 2015*

**Physics**

conserve momentum: .86m = .63*61
*December 2, 2015*

**Spga**

If the height is h, then h cot45° - h cot60° = 10
*December 2, 2015*

**math**

20,000
*December 2, 2015*

**Maths**

this is not a PDE Does the ellipsis indicate more terms? That xy term should indicate a saddle point.
*December 2, 2015*

**sunyani polytecnic**

3x^2 = 6y x^2 = 2y x = √(2y)
*December 2, 2015*

**Geometry**

clearly, the quadrilateral consists of two triangles, each with a base if 28 cm. Their altitudes are 6.8 and 8.0 cm. I'm sure you know how to find the area of a triangle, given its base and height...
*December 2, 2015*

**math**

the last digit must be 0 or 5. The first digit cannot be 0. So, count the choices for each place, and multiply it out.
*December 2, 2015*

**Mathematics 2**

t+u = 6 10u+t = 3t Find t and u; the original number is 10t+u.
*December 2, 2015*

**geometryproblems**

One side is x The next side is 2/3 x The last side is x+2 x + 2x/3 + x+2 = 98 Find x, then the short side is 2/3 x.
*December 2, 2015*

**Algebra**

express all as the same power of 10. Then it will be easy to sort them.
*December 2, 2015*

**solid mensuration**

probably 1/9, but I have no diagram to consult.
*December 1, 2015*

**Please help**

20min = 1/3 hr, so 2mi/(1/3 hr) = 6mi/hr downstream 2mi/1hr = 2mi/hr upstream 2mi/(4mi/hr) = 1/2 hr It's not clear whether somewhere in all that you are to find Lisa's speed in still water, and the stream's speed...
*December 1, 2015*

**math**

(2m)^3 * 1000kg/m^3 = 8000kg
*December 1, 2015*