# Posts by Steve

Total # Posts: 51,190

Math
a:p = 2:1 = 10:5

Math
2 negatives negative to odd power is negative

Math
log16 - 2logx

Math
what is the mean proportional for any two numbers?

math
consider a hexagon. The triangle's sides join alternate vertices of the hexagon.

maths
you want to divide the length into 9 equal parts. Place z 4/9 of the way from x to y.

#1 ok #2 4^x grows faster than any polynomial #3 I think more likely (-4,0), as in y = 2sin(pi/4 x) http://www.wolframalpha.com/input/?i=2sin(pi%2F4+x)

English
A little-known fact is that "shall" is used for first person: I shall arise and go now. "will" is used for 2nd and 3rd person. They will have a great time. These are reversed in the imperative mood. That is why the Ten Commandments read Thou shalt not steal...

Math
For the code, something like count=0 for i=1..2000   with student[i] do {     read   name,sex,score     pct = score*5/2     sub45 = false     if pct < 45 then   &...

math
surely you meant If the diagonal of a square is 14 m, what is the area? well, if the diagonal is d, the area is d^2/2 because if the square's side is s, the area is s^2. The diagonal is s?2, so d^2 = 2s^2

English language
if the predicate contains two nouns, usually one will be a direct object, and other the indirect object. The indirect one answers the question: to whom? or for whom? so, what are your choices? Not all of the sentences contain both objects.

English language
usually, the first noun in the sentence is the subject. After that, the rest is predicate. What are your choices?

maths
YZ = 2(6 sin50°)

maths
how do the two figures relate? One diagonal of a rhombus does not tell you anything about its sides or angles.

maths
as with all triangles, the smallest angle is opposite the smallest side. So, it is opposite the side of 5cm, and tan? = 5/8

math
just plug it into the formula: 15000(1+.095/4)^(4*5)

Math. HELP!
#1. remember the slope-intercept form? y = mx+b #2. The slope is (1+3)/(3-1) = 2 So, the point-slope form is y-1 = 2(x-3) Now rearrange that into slope-intercept form. #3 -4y = 8x so, y = -2x for the equation y = kx, k is the constant of variation #4. y = kx, so y/x = k, a ...

math
S = a/(1-r) a = 2r, so 2r/(1-r) = 4 Now just solve for r, and you can then get A3 = ar^2

math
-48/6 = r^3 Now you can figure a, and then S11 = a(r^11-1)/(r-1)

math
a+39d = -54 S15 = 15/2 (2a+14d) S30 = 30/2 (2a+29d) So, 15/2 (2a+14d) + 30/2 (2a+29d) = 0 or, a+12d = 0 Now you have two equations, and you can find a and d, and then the sum S40.

math
no way for me to see. However, check your graph against this one: http://www.wolframalpha.com/input/?i=y%5E3+%3D+x-2

mathematics
but there are many online articles that show how to do it.

Mathematics Algebra
But (x^2 + 2x +4)/(x^2 - 2x - 4) does not always fit into the interval [1/3,3]. If x is very close to 1±?5 then the value is arbitrarily large f(3.2) = -129 plus, you have a typo. I think you mean [9.(3)^2x + 6.(3)^x + 4]/[ 9.(3)^2x - 6.(3)^x +4] using u = 3.3^x That ...

maths
huh?

Mathematics
"real"ize the denominator by multiplying top and bottom by 1-i sinx. Now you have [tan 2x - i(sinx+cosx)][1 - i sinx]/[(1-i sinx)(1+i sinx)] [tan2x - (sinx+cosx)(sinx) + i(junk)]/(1+sin^2 x) to get zero real part, we need tan2x = sin^2x + sinx cosx any multiple of ? ...

Math
For the code, something like count=0 for i=1..2000   with student[i] do {     read   name,sex,score     pct = score*5/2     sub45 = false     if pct < 45 then   &...

Math
If there are x cars and y yellow cars, clearly the new car is yellow, since 1/9 > 1/10 y = x/10 y+1 = (x+1)/9 There are now 81 cars, with 9 yellow.

trigonometry
draw the diagram, and it is clear that the distance x is x/100 = tan 50°11'10"

Math
c+d = 500 .75c + .50d = 275

math
so, you used 304 ft of fence.

Math, factoring
Divide by (x^2-x-6) and you get quotient: x^2+(a+1)x+(2a+7) remainder: (8a+24)x + b+6(2a+7) For the remainder to be zero, we need a = -3 b = -6 So, x^4-3x^3-3x^2+11x-6 = (x+2)(x-3)(x^2-2x+1) The other roots are 1,1

Algebra
multiply the 2nd equation by 12 and you have 12y = -3x+20 or 3x+12y = 20 so, the two equations are the same.

Math (Double checking trig identity)
Nope. my bad. Still you were also wrong (a^2sec?)^2 - (a^2)^2 = a^4 (sec^2?-1) = a^4 tan^2?

Math (Double checking trig identity)
not at all. (a^2sec?)^2 - (a^2)^2 = a^4 (sec^4? - 1) = a^4 (sec^2?-1)(sec^2?+1) = a^4 tan^2? (sec^2?+1)

Cornhole
if you want names, puntarelli pamela kathryn huckaby

Math
No, ?35 is a number like any other, so it has to be included Just as 20+10x is not 30x, 20 + 10?35 is not 30?35 20?35 + 10?35 = 30?35 20+10?35 = 10(2+?35)

math
c'mon -- just start plugging in values for n: n=1: 1(1-2)-3 = -4 n=2: 2(2-2)-3 = -3 n=3: 3(3-2)-3 = ... and so on

Science physics
work is in Joules 2.0kg * 9.8 m/s^2 * 4.5m = 88.2 kg-m/s^2 = 88.2N-m = 88.2J work = force * distance force = mass * acceleration

Science physics
The acceleration is due to gravity g = 9.8 m/s^2

Math
correct

Math
since the ratio of height:shadow is the same, h/5 = 2/3

math
draw the two circles, and a line through their centers. Label the radii, and it should be clear what the two distances are.

maths
not sure just what you want to do with this log 5 = 0.699 I guess you can take it from there.

Math
(3 3/4)/3 = 1 1/4 Just divide everything by 3

Algebra
If the ... indicates some set of repeating digits, the number is rational If not repeating, then it is irrational Either way, it is real

Math-age problem
f+g = 60 f+6 = 2(g+6)

Math
j = e+5 j-3 + e-3 = 17 now just find 21-j

Math
those numbers are all volumes. You need to find pairs of numbers. The sum of their products is the area. Better yet, study the net to see which vertices of the prism are represented; then use what you know about prisms to get the area.

algebra
nope. the area will be 1/13^2 as much.

algebra
correct

math
2/3 as many men, so 3/2 as much time.

algebra
no, it will grow by a factor of 4^2 = 16

Algebra
just divide term by term, using the distributive property: (4x³ + 10x² + 3a) ÷ 2x² = 4x³÷2x² + 10x²÷2x² + 3a÷2x² = 2x + 5 + 3a÷2x²

Math
since east is +x and south is -y (-10,6)+(3,-12) = (-7,-6)

precal
No. If you want to find the probability that the marble you drew is blue or green, then that is just the 2/9, since 2 of the 9 marbles are either blue or green. If you mean that after the 1st marble was drawn and not replaced, what is the chance of then drawing a blue or green...

Calculus
you can do this as shells or washers. with shells of thickness dy, remember that the volume of a shell is 2?rh. So, draw the region, and ?[0,2] 2?rh dy For discs with holes, of thickness dx, work with ?[1,2] ?(R^2-r^2) dx your job is to examine the region in question and ...

physics
see related questions below

Math
see related questions below

Science
Just add up the displacements and see where you end up. The final displacement is just minus that location. For example, 50m in the direction 30degree west of north is <-50sin30°,50cos30°> = <-25.0,43.3>

algebra2
Find the sum of the following series. 14/n-=1 (2n+1)

Algebra2
What is the 50th term of the sequence that begins -2,4,10,16? My answer is 292

math
correct.

Functions
well, (fg)(x) = f(x)*g(x) = (x^2+3)(2x+a) expand that out and equate it to 4x^2-8x+7. The coefficients must all match. That will give you the value of a. Better check for typos, since fg = 2x^2 + ... and there's no way to match that with 4x^2+...

Physics
you know that with initial velocity v, s = vt + 1/2 at^2 Now just find s(10)-s(0) and s(20)-s(10) to find a and v.

Precalculus
C(x) = 396x + 12320 The price must depend on x if there is a maximum (P is a quadratic), so let's say it is 452-kx. R(x) = x(452-kx) = 452x - kx^2 P(x) = R(x)-C(x) = -kx^2 + 56x - 12330 Without some further data, I cannot say what is the value of k.

Math
what is 20% of 50?

Algebra
since 33% are girls, and 50% have black hair, some boys have black hair.

Math
if we set the center of the base at (0,0) then the parabola is modeled by the equation y = 5/2 - 5/18 x^2 Solve for x when y=2, and the beam has length 2x.

math
9!

maths --plse help me..
Hmm. I got 6 and 9 Better read the problem again. You got your division backwards: the greater divides the sum.

maths --plse help me..
If x < y, then we have (x+y)/(y+1) = 3/2 (y-x)/x = 1/2 Now just solve for x and y

Science
well 18g of steam is 1 mole of H2O So, write the balanced equation to see how many moles of Fe will be used. Then get the mass from that.

math
the girls walks on a heading, not a bearing. B's bearing from A is 78° If A is at (0,0), then B is at (279,59) If we mark point D due east of A, on the line BC, then D is at (279,0) Now, if angle DAC is ?, then cos? = 279/307 ? = 25° So, A's bearing from C is ...

math
use the law of sines. The distance z is z/sin91 = 4/sin44

MMATH08
well, since the 10 tiles cover the floor, each must have area 8000/10 = 800m^2 so, the tiles must have side length 20?2 unfortunately, you cannot cover a square floor with 10 square tiles, since 10 is not a perfect square.

Msth
just subtract the picture area from the total: (20)(30)-(20-10)(30-10)

Geometry
(x,y) -> (x-4,y-8)

Kaylee - banned
lim n->? of n ? (5+k(2/n))10(2/n) k=1

Probability and Statistics
If you plug some of your numbers in at this web site, I think you'll soon see how things work. http://davidmlane.com/hyperstat/z_table.html

Trig
not bad, but why did you subtract? d/dx (x+8)^(1/2) = (1/2)(x+8)^(-1/2) your derivative is good, except for that.

Math
to find r, note that a9/a4 = r^5 then use that to find a1

math
nope. P(heads) = 1/2 P(n<5) = 4/6 = 2/3 so, P(heads, n<5) = 1/2 * 2/3 = 1/3

Algebra
well, I guess you know the answer, then, right?

Algebra
none. You need two factors of 24 which differ by 1. Check for typos 1,24 gives 23q 2,12 gives 10q 3,8 gives 5q 4,6 gives 2q

algebra
2^(3/4) ----------- = 2^(3/4 - 1/2) = 2^(1/4) 2^(1/2)

Music
I guess you have picked the best answer Unlike a piano, whose strings are hit with hammers, and whose volume can vary (piano-forte), a harpsichord's strings are plucked (like a harp's) and always play at the same volume. Listen to some recordings and it's easy to ...

English
could is the past tense of can I can swim well. Yesterday I could swim well. Then there are the conditional and perfect uses, but maybe you're not after those.

physics
watch the units wavelength(m) = speed(m/s) / frequency(1/s)

Math (Calculus II) (Partial Fraction Decomposition
So, you have two polynomials, which are identical. That means all the coefficients on both sides must be the same. That is, x = B(x^2+a^2)(x-a) + C(x+a)(x^2+a^2) + (Dx+E)(x+a)(x-a) = B(x^3-ax^2+a^2x-a^3) + C(x^3+ax^2+a^2x+a^3) + D(x^3-a^2x) + E(x^2-a^2) = (B+C+D)x^3 + (-aB+aC+...

Math
They all look ok to me, except #2. Recall that the slope is ?y/?x pick any two pairs and see what you get #3. Note that y increases by 5 for each step. You could not possibly have tried 3x+6 on more than one pair. #5. Again, you clearly only tried n=1.

Math
No. There were 10 tosses. 8 of them showed at least one H So, P = 8/10 = 0.8

Math
you have it exactly backwards. 0.2 is the probability that NO heads showed.

Physical Science
well, 1/16 = 1/2^4 so it takes 4 half-lives

Math
16

Math
6":18' = 1:36

math - try again
fix the typos and post it again.

math
each man does 1/(24x) in a day each woman does 1/(32(x+8)) in a day so, 15/(24x) ------------ = 3/1 12/(32(x+8)) yes, x=10

science