Tuesday
May 24, 2016

Posts by Steve

Total # Posts: 40,760

Math Algebra 2
y = a(x-p)(x-q) using three different values of a will produce three different polynomials. Graphing them will produce parabolas that all cross the x-axis at the same two places (if at all), but are scaled differently.
April 3, 2016

Trig
recall that cos(a-b) = cosa cosb - sina sinb
April 3, 2016

Math
f = (2-3x)/(5-2x) f(a) = 3 when (2-3a)/(5-2a) = 3 2-3a = 15-6a 3a = 13 a = 13/3
April 3, 2016

Math
the pyramid has 1/3 the volume of the prism. Why wait for hours, when google can show you many discussions and formulas?
April 3, 2016

maths help!
know the density? mass = density * volume
April 3, 2016

Math
pyramid has 1/3 the volume of the prism.
April 3, 2016

Maths
tan^2(x/2) = (1-cosx)/(1+cosx)
April 3, 2016

Maths
sinx + sin3x = 4sinx cos^2x = 2sin2x cosx So, you have (2sin2x cosx - 2sin2x) --------------------------- (2sin2x cosx + 2sin2x) 2sin2x(cosx-1) --------------------- 2sin2x(cosx+1) = (cosx-1)/(cosx+1) Now take a look at the half-angle formula for tan(x/2)
April 3, 2016

maths
x^3-2x^2-13x-10 = (x+1)(x+2)(x-5) x^3-8^2 = (x+4)(x^2+4x+16) Looks like the LCM is just the product, since there are no common factors. Not sure what the minuscule has to do with it.
April 3, 2016

Springville Middle School
1/3 * pi * 15^2 * h = 7800
April 3, 2016

Math
h cot30 - h cot45 = 6
April 3, 2016

Algebra
{3,6,9,...}
April 3, 2016

math
clearly there were 3 times as many pears as oranges. So, 20 oranges.
April 3, 2016

maths
Is there a question somewhere in there?
April 3, 2016

MATH
if you are given only two of the dimensions, there is no way to determine the third. You need to know the volume, or the area, or a diagonal -- something to pin down that third dimension.
April 3, 2016

cs203
google is your friend. You might start here: http://stackoverflow.com/questions/14622371/how-do-i-print-a-binary-number-with-an-inputed-integer
April 2, 2016

algebra
or, since you have a point and a slope, you can just use the point-slope form: y-5 = 3(x-4)
April 2, 2016

Math
As long as the same dimension was used for rolling, the circumference is the same and the height is the same. So, the radii are the same, and both cylinders have volume π r^2 h.
April 2, 2016

math
okay. You know that all the s^(4x) and e^(-4x) stuff will zero out. So we need some quadratic stuff that will leave a particular solution. So, let's say that y_p is yp = Ax^2+Bx+C yp" = 2A yp" - 16yp = 2A - 16(Ax^2+Bx+C) So, we need -16Ax^2 - 16B + 2A-16C = 256x^...
April 2, 2016

Mathematics
(1-4)/(2-1) = -3/1 = -3 Clearly you need to plot the points and take a look at the line. + slopes are rising to the right - slopes are falling to the right
April 2, 2016

Math
clearly, 1275/1700 = ?
April 2, 2016

Mathematics
(1-3)/(-2-2) = -2/-4 = 1/2 Gotta watch those plus/minus values.
April 2, 2016

math
It's bad form to describe N(p) and then talk about x and y. Clearly, the N intercept is at -2818. What is p when N=0? Care to reconsider your answer?
April 2, 2016

math
Actually, it's the w-intercept in this case. At any rate, at the intercept, m(w)=0. That is, no money remains.
April 2, 2016

algebra
3/4 of 60 is 45 mi 45mi/9hr = 5 mi/hr what was she driving, a roller skate?
April 2, 2016

Geometry
h = 7√3, so each side is 14 A = (1/2)(14)(7√3) = 49√3 P = 3*14 = 42
April 2, 2016

maths
since (a+b)(a-b) = a^2-b^2 √3-√2 * (√3+√2)/(√3+√2) = (3-2)/(√3+√2) I assume by ig you mean log log(√3-√2) = -log(√3+√2)
April 2, 2016

Calculus
(x-3)^(2n)/4^n = (x-3)^(2n)/2^(2n) = ((x-3)/2)^(2n) So, as long as |(x-3)/2| < 1 it will converge.
April 2, 2016

math
Note that log_2(n) = 2*log_4(n) = 3*log_8(n) a = log_4(y) = (1/2) log_2(y) b = log_8(2y) = log_8(2) + log_8(y) = 1/3 + (1/3) log_2(y) b = 1/3 + (2/3) a 3b = 1+2a If logn = logm + 1, logn = logm + log10 = log(10m) so, n = 10m
April 2, 2016

math
20*8-20*5 = 20(8-5) = 60
April 2, 2016

math
8x + 5x = 260 find x, and then the amounts are 8x and 5x. Subtract to get your answer.
April 2, 2016

Geometry
Each leg is 10/√2, so P = 2*10/√2 + 10 = 10(1+√2) A = (1/2)(10/√2)(10/√2) = 100/4 = 25
April 2, 2016

Math
exactly.
April 2, 2016

Math
remember that distance = speed * time so, plug in your numbers.
April 2, 2016

Math
just multiply everything by 3!
April 2, 2016

Math
consider the sales tax. If it is 5%, the the final price is the retail price times 1.05, right? So, if our tax rate is r (expressed as a decimal), then the final cost of 70.75 is (1+r) times the sticker price. The tax amount is the final cost minus the sticker price: 70.75 - ...
April 2, 2016

Math
70.75(1-1/(1+r)) = 5.66 r = 0.0869 = 8.69%
April 2, 2016

maths-help!!
well, 240 = 4*60 so 2n can be any value from 0 to 58 so, n ...
April 2, 2016

math
(n*1.60)/(d*0.80) = (n/d)(1.60/.80) = (n/d)(2) so, the fraction is doubled. What percent increase is that? And it is not 200%!
April 2, 2016

math
(a*1.50)(b*0.80) = (ab)(1.20) so, the product increased by 20%
April 2, 2016

math
I can't quite picture your diagram, but 40 is 5/9 of the whole area. Maybe you can use that to get what you're after.
April 2, 2016

math
If each light consumes h watt-hours, then 4 lights running for n hours consume a total t of t = 4h*n Plug in your numbers. I can't figure out just what you're after.
April 2, 2016

math - eh?
Can you see how woefully incomplete your information is, if you want a solution?
April 2, 2016

Math - incomplete
why is x zero twice? Given your "table," I can fill in any numbers I want.
April 2, 2016

maths
S+H+J = 500 J = 3S S+33 = (5/6)(J-33) Oddly, I don't get integer solutions. Better check the problem and my setup.
April 2, 2016

Computer science
sure. That's why some computer folks are called systems analysts. Their basic software is called an operating system.
April 2, 2016

Mathematics
nope. (1-5)/(3-6) = -4/-3 = 4/3 better review the definition of slope.
April 2, 2016

Mathematics
did you plot the points? both have -3 for the x-coordinate, so the line is vertical. did you do the actual calculation? change in y divided by change in x? (-6 - -5)/(-3 - -3) = -1/0 is undefined.
April 2, 2016

Math(PLZ HELP)
#1 kg?? Really? That's over 2 lbs! Your paper clips must be a lot bigger than mine. #2 see #1 #3 ok #4 ok #5 ok #6 ok #7 a 15 ft border is added to each side, making both width and length 30 ft more. So, the new dimensions are 26+30 by 21+30 = 56 by 51
April 1, 2016

Math
Make a Venn diagram, and you can easily see that there are 70 students taking at least one of the classes, and thus 37 taking no class. Using the diagram, you can easily see how many students fit the questions; and thus the probabilities needed.
April 1, 2016

Math (Real Analysis)
epsilon-delta proofs use limits. abs(f) is continuous if f is continuous, because |f| = f if f>=0 |f| = -f is f<0 So, if the limit L exsists for f(x), it also exists for |f(x)|.
April 1, 2016

math
1 lb = 16 oz 3 lb = 48 oz You have given the number of lbs in 3 oz.
April 1, 2016

trigonomentry
no diagram, but I suspect that the Pythagorean Theorem can be used here.
April 1, 2016

math
no idea. There must be some other information here. If you know the height and the width, the length can be anything unless you also know the volume or area or a diagonal.
April 1, 2016

math
correct.
April 1, 2016

math
miles = 6 * minutes
April 1, 2016

Dosage calculations
1 tsp * 4.93 mL/tsp = 4.93 mL All that other stuff about number of days and number of doses is just noise.
April 1, 2016

umd
ok. Now what?
April 1, 2016

Algebra 2
font problems. Is that supposed to be sigma = 3.1? If so, just figure the mean, and find the maximum difference of each grade from the mean. Then divide that by 3.1 to get the number of std.
April 1, 2016

math
5.4ft/180m = 1.65m/180m = 1:109
April 1, 2016

Math
x changes by 1, y changes by -5 So, look for something like y = -5x Now adjust that so it fits.
April 1, 2016

Math
2340 + 100 - 50
April 1, 2016

Math
well, just plug in the x value and see whether you get the y value. For example, when x=0, 2*0 - 3 = -3 Nope, You want 3. Now try the others. One will work.
April 1, 2016

Maths
.40*30 = x(30+45) x = .16 or, since the volume has grown by a factor of 5/2, the concentration has been reduced by a factor of 2/5 to 16%
April 1, 2016

trig
Draw the triangle. sinθ = y/r cosθ = x/r tanθ = y/x In QII, y = 3 x = -4 r = 5 so, cosθ = -4/5 tanθ = -3/4
April 1, 2016

Trig
so, cos(x) = 1/7 and x is in QI or QIV so, x = 81.79 or 278.21 degrees no idea where you came up with your values for sin(x) and tan(x). ??
April 1, 2016

Math
you have to add x on each side, or 2x to both dimensions. So the perimeter is 2(5+2x+ 10+2x) = 30+8x
April 1, 2016

math
7:35
April 1, 2016

Calculus
draw your triangle You have the opposite leg=12 and the hypotenuse=13 So, the adjacent leg is √(169-144) = 5 cot(x) = 5/12
April 1, 2016

Math
If you mean ln(23x)+1 = 5 ln(23x) = 4 23x = e^4 x = e^4/23 If you mean ln(23x+1) = 5 23x+1 = e^5 x = (e^5-1)/23 Get used to being specific online.
April 1, 2016

Math
If x at 12%, then .12x + .15(5000-x) = 700
April 1, 2016

Brief Calculus
f' = 12x^2 - 18x - 30 Now use your Algebra I skills. (A) the critical numbers are where f'=0 (B) f is increasing where f' > 0.
April 1, 2016

precalc
Using the usual formulas, sin42°+sin18° = 2 sin30° cos12° since sin30° = 1/2, that is just cos12° = sin78° cosine means sine of the complement.
April 1, 2016

Math
if the drawing is 1 x 1.25 inches, then clearly each inch represents 20 feet.
March 31, 2016

Math
multiply all the numbers by 7 so that the largest is 42. 14:21:35:42 that should help.
March 31, 2016

Mathematics
so, if you plug in 12 for t, how do you get 12/3 = 15? You apparently did 12+3=15 better review what the operators mean.
March 31, 2016

Mathematics
well, it's bogus. It's already a whole number of dollars. Rounding to the nearest dollar doesn't mean anything unless there are some cents. $2200.51 rounds up to $2201 $2200.23 rounds down to $2200 $2200 rounded to the nearest thousand is $2000
March 31, 2016

Math
Draw a diagram. If the base of the rectangle is the segment (a,0) to (b,0) then the upper vertices are (a,4a) and (b,6-5b). Since it is a rectangle, the height is the same, so 4a = 6-5b. That is, b = (6-4a)/5 Now, the area is (b-a)(4a) = ((6-4a)/5-a)(4a) = 12a/5 (2-3a) This is...
March 31, 2016

pr calc 11
The quadratic formula works with all quadratics!! h = -0.09x^2+x+1.2 h(x) = 0 when x = [-1±√(1^2-4(-.09)(1.2))]/(2(-.09) = (-1±√1.432)/-0.18 = -1.09 or 12.20 Now, how does that answer the question? It means that when the water shoots out, it will hit ...
March 31, 2016

pr calc 11
just solve h(x) = 0
March 31, 2016

algebra
Since time = distance/speed, d/24 + 1/6 = d/30
March 31, 2016

Math 142 (Pre-Cal) (Circles)
looks good to me.
March 31, 2016

math help pls pls pls
correct.
March 31, 2016

math help pls pls pls
Assuming you know what the standard form is (highest degree first), then can you determine the degree of each term? Just add exponents of all the variables. what if two terms have the same degree? I have checked a few discussions, and none mentions that wrinkle. Check your ...
March 31, 2016

algebra 1
$42
March 31, 2016

algebra
just sub in2x+2 for y x^2+3x-4 = 2x+2 x^2+x-6 = 0 (x+3)(x-2) = 0 ... or, without solving, you could just check each of the choices... duh
March 31, 2016

Math
If the sides in order of length are a,b,c then b = a+7 c = b+2 = a+9 a^2+b^2 = c^2 a^2+(a+7)^2 = (a+9)^2 a=8, b=15, c=17 I think you can take it from there, right?
March 31, 2016

Hi need help with math
what's all this shape stuff?
March 31, 2016

algebra
all those words! f(x) = |x| if -3 <= x < 1 4 if 1 <= x <= 8 Just plot each line, and mark off the sections you want. http://www.wolframalpha.com/input/?i=plot+[piecewise+[{{|x|,+-3%3C%3Dx%3C1},{4,+1%3C%3Dx%3C8}}]]
March 31, 2016

College Algebra/pre-calculus
since the value starts at $8000 and decreases by 7000 in 10 years ($700/year), the equation for the value is y = 8000 - 700x at x=6, y = 8000 - 4200 = 3800
March 31, 2016

math
a constant rate (slope) means a linear function. So, which of those is linear?
March 31, 2016

Math
of the 52 cards, how many are a heart or a 10?
March 31, 2016

math
P(pop) = 9/92 so, P(0 pop) = (83/92)^13 P(1 pop) = 13C1 (9/92)(83/92)^12 add them up
March 31, 2016

vectors
suppose we say that vectors u = force of 125 N pulls due west v = force of magnitude v pulls N 28.79 W r = resultant force is 212 N at angle b expressing those in x-y coordinates, u+v = r <-125,0> + <-v sin 28.79,v cos28.79> = <212 cosb, 212 sinb> <-125,0&...
March 31, 2016

Algebra 2
correct all the way. Good work.
March 31, 2016

Geometry
.015mi * 5280 ft/mi / .005hr * 1hr/60min * 1rev/2πft = 414.69 rev/min
March 31, 2016

Solid Mensuration
what is the cross-section?
March 31, 2016

Geometry
a = πrs, so 46πs = 736π s = 16
March 31, 2016

Math
1/42^42
March 31, 2016

Algebra
x + x/7 = 88
March 31, 2016

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