Thursday
August 25, 2016

Posts by steve

Total # Posts: 42,774

Algebra
count the tickets: g+s = 215 count the dollars: 10g+6s = 1990 Now crank it out.
July 7, 2016

Geometry
rewrite as y = 2x-3 and you can read off the slope and intercept
July 7, 2016

Pre-Cal
oops sinx = 8/17 so, cosx = 15/17 sin2x = 2 sinx cosx = 2 * 8/17 * 15/17 = 240/289
July 7, 2016

Pre-Cal
sinx = 8/17 so, cosx = 15/7 sin2x = 2 sinx cosx = 2 * 8/7 * 15/7 = 240/49 do the others similarly.
July 7, 2016

Algebra
Huh? It's already written out. That's how I got the equation. Can you not solve the equation? If you find x, that's how many lbs of worms you need. The rest (30-x) is bears.
July 7, 2016

Algebra
If x lbs of worms, then 7x + 3(30-x) = 4.60*30 This is just like the interest problem, which is also a mixture problem.
July 7, 2016

Pre-Cal
recall that tan(x-y) = (tanx-tany)/(1 + tanx tany)
July 7, 2016

Algebra
If $x is at 8%, then .08x + .09(10000-x) = 860
July 7, 2016

Physics - tense
I'm waiting for the answer here... Talk about tension!
July 7, 2016

Maths
Yeah, I noticed that. I can't figure why the closest answer is so far off. To get 12.2 years, r needs to be 9.58%
July 7, 2016

geometry
review your basic trig functions, and from a distance of x feet, 1149/x = tan 89° Now just solve for x.
July 7, 2016

Calculus
recall that the range of an object is R = v^2/g sin2θ so, figure some pairs of value that make that 100 miles. Of course, that formula implies a flat earth, and 100 miles is far enough away that varying gravity and earth's curvature require some modifications.
July 7, 2016

Maths
For n sides, there are n-2 straight angles, or 2(n-2) right angles. So, n=17
July 7, 2016

MATH Function Transformation
If you mean a polynomial such as a(x-p)(x-q)(x-r)... then a is the vertical scale value, so a = 1/2 means the y values are half as big: a compression ratio. stretching and compression are just two ways of looking at a scale factor. Usually a compression means a < 1 and a ...
July 7, 2016

Math
75 min = 1.25 hours, so 15.4mi/1.25hr = 12.32 mi/hr
July 7, 2016

math
that is one way. The other way is to use the Remainder Theorem and evaluate f(1). That is the remainder R.
July 7, 2016

Math Please Help
you just want d(t) > -16 t^3-9t^2+6t > -16 t^3-9t^2+6t + 16 > 0 (t+1)(t-2)(t-8) > 0 Now, using what you know about the general shape of cubics, you know that this one will come up from the lower left, then cross the t-axis at -1,2,8. Since it started out negative, ...
July 7, 2016

math
review your basic trig functions: h/450 = tan 20°
July 7, 2016

algebra2
If there are x cows and y chickens, you know (counting heads) x+y = 35 Now, counting legs, you know: ??? Work that out, then solve the two equations.
July 7, 2016

AB Calculus
Assuming all logs are base b (since the base does not matter for this kind of stuff), we have (I think) log ∜(x^7 y^2 / z^4) = 1/4 log(x^7 y^2 / z^4) = 1/4 (7logx + 2logy - 4logz) = 7/4 logx + 1/2 logy - logz or, (b)
July 7, 2016

math
Since y has an absolute maximum, it must be of even degree, since all the odd-degree polynomials go forever in each direction. And, its leading coefficient must be negative, since the graph opens downward.
July 7, 2016

Maths
Since multiplying logs is not one of the usual operations, and none of the answers includes (x-6) I'd say you are in trouble from the start. I suspect that you were given -2logb^x -6logb^y + 1/7 logb^z That is choice (a), assuming the usual sloppiness with notation.
July 7, 2016

math
A little synthetic division shows that the remainders are -9m-92 and 23-4m If they are equal, then m=-23 P(-3) = P(2) = 115
July 7, 2016

Advanced Function
the volume increases by the cube of the linear scale. So, he needs a scale factor of no more than ∛9 = 2.08
July 7, 2016

geometry
well, you know that m∠ABE is half of the total, since BE bisects ∠ABD.
July 7, 2016

Maths
What's to figure out? They gave you the exact formula you need. 9% growth means it grows by a factor of 1.09 each year, so t = ln3/ln1.09 = ?
July 7, 2016

General Mathematics
8 + 1.5*ceil(x) for x km above 4. where ceil(x) (ceiling function) is the least integer greater than or equal to x.
July 7, 2016

Algebra
110*55 = ?
July 7, 2016

Science
30√2 SW is the same as 30S and 30W So, now add up all your distances and see where you end up. The answer will be surprisingly easy.
July 7, 2016

geometry
(B+b)/2 * h fill in the values
July 7, 2016

math
Not always. Never for rectangles.
July 7, 2016

AHOOGAAH! Homework Dump
No ideas on any of these?
July 7, 2016

Math
(3 + (2/3)(-3-3),(2 + (2/3)(5-2)) = (3-4,2+2) = (-1,4)
July 7, 2016

Math
well the slope of the line between (-2, -1) and (6, 8) is (-1-8)/(-2-6) = 9/8 now use the point-slope form of the line
July 7, 2016

Calculus
Let u = tan(π/4 sin(2x)) du = sec^2(π/4 sin(2x))*(π/4)(2cos(2x)) du So, what you have is just ∫du with some constant factored out.
July 7, 2016

General Math
since pure juice is 100% juice, add up the amounts of juice: .50(6) + 1.00(x) = .75(6+x)
July 7, 2016

physics PS
Oops -- v = 2/3 t^3 i + 2/3 t^2 j
July 7, 2016

kashinath palod
FF = ma = 6t^2i + 4tj Since m=3, a = 2t^2i + 4/3 t j so, v = 2/3 t^2 i + 2/3 t^2 j
July 7, 2016

Calculus
well, sin^2(x) = 1/2 (1-cos(2x)) that should be easy to integrate, right?
July 7, 2016

maths
I have never heard of the word kharch, but the apple's share is 5/(6+10+5) = 5/21
July 7, 2016

math
well, ADB is also an isosceles right triangle with sides of 5. So, its hypotenuse is AB = 5√2 that help?
July 7, 2016

Math
Well, the 1st term in the rth group is 1,2,4,7,11,... = 1+ 0,1,3,6,10 = 1+ r(r-1)/2 That should get you started.
July 7, 2016

Math
looks good
July 7, 2016

pre cal
6(x^2 - 2/3 x + 1/9) = 6(x - 1/3)^2
July 7, 2016

Pre-Cal
(csc θ − sin θ)/(cos θ) = (1/sinθ - sinθ)/cosθ = (1-sin^2θ)/(sinθ cosθ) = cos^2θ/(sinθ cosθ) = cosθ/sinθ = cotθ
July 6, 2016

Pre-Cal
(sin^2 + cos^2)/cos = 1/cos
July 6, 2016

java program
letter = (n>=90) ? "A" : (n>=80) ? "B" : (n>=70) ? "C" : (n>=60) ? "D" : "E";
July 6, 2016

Algebra
check the slopes. If their product is -1, the lines are perpendicular. That is, if one slope is the negative reciprocal of the other.
July 6, 2016

Math
Thunk of it using actual numbers. If he can mow the lawn in 4 hours, how much in 2 hours? 2/4 So, it will take him 2/x hours. If it takes him x hours, he does 1/x of the job in 1 hour. So, twice that, or 2/x in 2 hours.
July 6, 2016

math
ever hear of actual math symbols? 3√5 - 2√7 + √245 - √28 3√5 - 2√7 + √(49*5) - √(4*7) 3√5 - 2√7 + 7√5 - 2√7 10√5 - 4√7
July 6, 2016

MATH HELP
In 30 minutes, the first bus has gone 39 miles The 2nd bus goes 15 mi/hr faster. So, how long does it take to cover the extra 30 miles? It's the same as if the 1st bus stopped 30 miles away, and the 2nd bus drove 15mph to meet it.
July 6, 2016

Chemistry
sure looks like D to me twice the value, opposite direction
July 6, 2016

math
what, you cannot add 600+3200 ?
July 6, 2016

Normal Distribution
you can play around with Z table stuff at http://davidmlane.com/hyperstat/z_table.html
July 6, 2016

math
not sure what the scaling has to do with anything, as the scaled polygon is never mentioned. However, it should be easy to convince yourself that such a scaling does not change any of the slopes or angles involved.
July 6, 2016

Math
yes, it can. Because to be even f(-x) = f(x) This is true only (and always) if all the exponents are even.
July 6, 2016

Math
the highest exponent is the degree the order of a root is the number of times it appears. So, you have three roots of degree 1. Any polynomial of degree n has exactly n roots, though all may not be unique (order 1).
July 6, 2016

algebra 2-1
x=42
July 6, 2016

Pre Calculus
again, only one possible choice, since e^1 = 2.718 e^2 = 7.389 e^3 > 16
July 6, 2016

Pre Calculus
x = 5/2 Now if you mean 2^x = 5 The answer should be clear, since 2^1 = 2 2^2 = 4 2^3 = 8
July 6, 2016

Math
since time * speed = distance, and the two distances are the same, 60t = 70t + 3/2 find t, then use that to get the distance
July 6, 2016

maths
make that 100° (130-30)
July 6, 2016

maths
use the law of cosines: QR^2 = PQ^2 + PR^2 - 2 PQ PR cos 130
July 6, 2016

Math - eh?
between 20,000 and 40,000 2xxxx 3xxxx 4xxxx mumble mumble My hundred digit is the sum of my ten thousands digit. ???
July 6, 2016

math
The minute hand has advanced 25/60 = 5/12 of a circle, or 150° The hour hand at 6:00 is at 180°, and it has advanced 5/12 of the way to the 7, or 5/12 * 30 = 12.5° So, the angle is 12.5+30 = 42.5°
July 6, 2016

math
no drawing here
July 6, 2016

math
at what time?
July 6, 2016

Math (Analytic Geometry)
Assuming you just want verification of your results, 1. y + 5/2 = 6/5 x 2. (x+8)^2+(y-8)^2 = 4((x+2)^2+(y-2)^2) or, x^2+y^2 = 32 3. Clearly this is the ellipse with foci at the two points, and a=6, c=4, b^2=20 x^2/36 + y^2/20 = 1 see http://www.wolframalpha.com/input/?i=...
July 6, 2016

See a Therapist
You clearly have a split personality and can't even tell that you keep posting the same problems again and again.
July 6, 2016

Analytic geometry
they lie on the perpendicular bisector of the line between the two points. That line has slope -5/6, so its perpendicular has slope 6/5 The midpoint of the line segment is (0,-5/2), so the line you want is y + 5/2 = 6/5 (x-0)
July 6, 2016

MATH
you need to cut off a slice 2√5 wide.
July 6, 2016

arithmetic sequence
A9 = A1 + 8d
July 6, 2016

arithmetic sequence
there are 4 terms past the first, so divide 92/4 to get the difference between terms
July 6, 2016

arithmetic
10000
July 6, 2016

math
what are the factors of 65? 5 and 13 looks like they work
July 6, 2016

Math
a+2d = 8 a+8d = 3*8+2 so, a=2 and d=3 Now you want S19 = 19/2 (2*2 + 18*3)
July 6, 2016

Meths
since distance = speed * time, 60t + 11/2 = 70t Now you have the time it takes, so you can find the distance.
July 6, 2016

Math
vertical asymptotes: y = 1/((x+6)(x-7)) y(6) = 0, so y = (x-6)/((x+6)(x-7)) horizontal asymptote at y = 10/9 needs a quadratic on top, so we could have y = (10/9)(x-6)^2/((x+6)(x-7)) but that does not really cross the x-axis at x=6, but just touches it. So, how do we get that ...
July 6, 2016

Phisics
measured in Joules. So, look up the definition of a Joule.
July 5, 2016

chem 121
just plug in your formula PV = nRT n = PV/RT n is the number of moles. Now multiply by A, Avogadro's constant to get the number of molecules. Or, since R = kA, n = PV/kAT so nA = PV/kT gives the number of molecules
July 5, 2016

math-steve
Hmmm. I drew a tree with all possible outcomes, but I forgot to weight each branch with its probability. Try doing that and see what happens. I'll try to get back later.
July 5, 2016

Science
at time t, s = 20t + 1/2 a t^2 so, we can find a by solving 20*30 + 1/2 a * 30^2 = 1200 a = 4/3 m/s^2 v = 20 + at = 20 + 4/3 * 30 = 60 m/s
July 5, 2016

Math
I'll assume that s is the length of a side. After the borders are discarded, an (s-2)x(s-2) square remains. There are 2(s-2)-1 = 2s-5 squares on the diagonal, so the remaining squares number (s-2)^2 - (2s-5) = s^2-6s+9 = (s-3)^2 you can easily check this for small s.
July 5, 2016

Pre Calculus
Since log(xy) = log(x) + log(y) regardless of the base, and considering the chance of typos, I'd go with (e)
July 5, 2016

science
sets of vectors? 10,20,30 are just three scalars. Try again.
July 5, 2016

Math
well, 15 1/2 = 15.5 So I'd guess 2.155 but that's certainly an unusual way to express a value. In fact, I'd guess it's a typo. I've never seen a mixture of decimal and fraction like that.
July 5, 2016

Maths
use your sum-to-product formulas: cosB-cosA = 2 sin (A+B)/2 sin (A-B)/2 cosA+cosB = 2 cos (A+B)/2 cos (A-B)/2 now just divide
July 5, 2016

math
1/10 to end up with exactly 27 6/10 to end up with at least 27 4/10 to lose
July 5, 2016

math
22+25-2
July 5, 2016

Pre-Calculus 11
2∛3 + 5∛3/4 = ∛3 (2+5/4) = ∛3 (13/4) or maybe 2∛3 + 5∛(3/4) = (5+2∛4)∛(3/4) = 1/2 ∛3 (4+5∛2) -12√11 + 5√11 = -7√11 Other than that I don't see much joy
July 4, 2016

math
875 * (1+2)
July 4, 2016

Math of investigation
Hmmm. I originally rejected the idea that the centers would lie on the diagonal, because I thought the circles would overlap or not fill the maximum area. I'm not sure how your equation comes about, but it appears you have solved the problem.
July 4, 2016

Object Oreinted Programming in java
not much object usage there. Just about a dozen lines of code, mostly I/O.
July 4, 2016

Economics/Finance
You don't say what he started with. Assuming $2000, at the end of year 2 he has 2000*1.05^2 at the end of year 4, he has 2000*1.05^4 + 2000*1.05^2 so, after 20 years, that's 10 investments, totaling 2000 (1.05^20 + 1.05^18 + ... + 1.05^2) Now, 1.05^2 = 1.1025 so that&#...
July 4, 2016

Pre Calculus @Reiny
Good job with the formatting!! Did you post somewhere in the past as a scratchpad?
July 4, 2016

Pre Calculus
A little synthetic division shows that f(x) = (x-(6+√6))(x^2+(√6-5)x+(√6-6))+2 I leave it to you to verify that f(6+√6) = 2
July 4, 2016

Math
a = πrs where 2πr = 132 s^2 = r^2+h^2
July 4, 2016

geometry
Draw a diagram. If the hat's radius is r, then r^2+r^2 = 15^2 and the diameter is just 2r
July 4, 2016

Math
just multiply the volume of metal by its density to get the mass: cm^2 * g/cm^3 = g You know that the volume of a sphere of radius r is v = 4/3 πr^3 so, to get the volume of metal, just subtract the volume of the empty inner sphere from the outer sphere.
July 4, 2016

Math
the mean of 2,3,5 is 10/3 So, to have a mean height of 30, each number must be multiplied by 9, giving heights in the ratios 18:27:45 If 4 plants have a mean of 33, their sum is 4*33 = 132 18+27+45=90, so the 4th plant has height 42
July 4, 2016

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