# Posts by Steve

Total # Posts: 52,318

**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**

ever hear of google? http://www.rsc.org/periodic-table/element/8/oxygen

**math**

42

**Math**

well, tan? = 180/215

**Algebra 2**

that's right.

**Algebra 2**

nope. If it has a maximum, then the graph turns back on itself, so it fails the horizontal-line test.

**Geometry**

Since they share a common diagonal BD, they are the same rectangle.

**Algebra 2**

f?g = f(g) = g^2-5g+6 = (x+3)^2-5(x+3)+6 = x^2+x

**Pre Algebra**

7^5 * 7^6 = 7*7*7*7*7 * 7*7*7*7*7*7 = 7^11 all 7's, no 49's

**Pre Algebra**

nope 7^5 * 7^6 = 7^(5+6) = 7^11 Better review the rules of exponents. The base does not change: a^m * a^n = a^(m+n) NOT (a^2)^(m+n)

**Algebra 2**

f(x)-g(x) = (x^2+2x-6)-(3x^2-5x-7) = x^2+2x-6-3x^2+5x+7 = -2x^2+7x+1 watch those minus signs when subtracting!

**Math Graphing**

http://www.wolframalpha.com/input/?i=y%3D+1%2F5x+-+2

**Math**

you are

**Trig help**

A is correct

**calculus review please help!**

for the integral, there are two ways. shells of thickness dx: v = ?[0,2] 2?rh dx where r = 5-x and h=x-x^2/2 v = ?[0,2] 2?(5-x)(x-x^2/2) dx = 16?/3 discs (washers) of thickness dy: v = ?[0,2] ?(R^2-r^2) dy where R=5-y and r=5-?(2y) v = ?[0,2] ?((5-y)^2-(5-?(2y))^2) dy = 16?/3 ...

**maths**

correct

**maths**

If you let u = 4x^2 v = 3-x then you have y = (u/v)^3 y' = 3(u/v)^2 (u/v)' = 3(u/v)^2 ((u'v-uv')/v^2) = 192x^5(6-x) / (3-x)^4

**maths**

All the steps in your work are correct.

**maths - try again**

all that duplicated text is impossible to parse. Try typing it in, rather than copy/pasting. Use t^2 for t squared

**Trig help**

C is correct

**Algebra**

come on. For #5, you have 5x-20y=60 5x-20y=60 They are the same equation. So, any solution to one is also a solution to the other. Try a similar comparison for #6 and just think about what it means.

**math help?!**

correct

**algebra**

15 < 5x

**Science**

correct

**AMth**

64/256 = 1/4 I don't see any matches

**calculus**

The sequence can be rearranged as 1/3, 1/4, 1/5, 1/6, ... ....1, 1/2, 1/3, 1/4, ... so, the terms converge to zero The sum, however, will come close to twice the sum of the harmonic series, which diverges.

**calculus**

2+3+4+... = n(n+1)/2 - 1 So, if N = n(n+1)/2 - 1, you know that the Nth term is 4, and the n+1st term is 0 So, while the number of zeros is infinitely many more than the number of 4's, the terms do not converge to either 4 or 0.

**calculus**

by this time you should know that exponentials always overcome polynomials.

**calculus**

since cos(x) oscillates between 1 and -1, the sequence does not converge. As n/8 comes arbitrarily close to multiples of pi, cos(n/8) will get close to 1 or -1.

**calculus**

since the terms are just basically 1/?n the sequence converges to 0

**precalculus**

the circumference of the wheel is just 2pi*r

**Geometry**

clearly, 10+1/2(8.7x6.7)=39.145 But, unless you provide some more information about B,P,I and their relation to the pyramid, it's hard to say whether that is really S.

**Math**

Since you give no indication of a horizontal speed, I don't see how just jumping up and down will get him over the building. However, his maximum height will be at x=200/32=6.25, so plug that in and see whether it is high enough. I suspect that you meant the f(x) gives the...

**History**

Have a good week.

**History**

It does because of all the lost jobs in the auto industry and sub firms supporting them. Just wanted to check for my grandson. thank you

**History**

Which of the following region's populations grew the slowest during the second half of the 1900's?) The Midwest The Southwest The Southeast The West Coast my answer is the midwest

**calculus**

If she walked x km, then since time = distance/speed, x/3 + (8-x)/7 = 2

**Math**

not quite a8 = a+7d = -3+7(-4) = -31

**Calculus**

draw a diagram. It is clear that tan? = x/25 so sec^2? d?/dt = 1/25 dx/dt 1.0353 d?/dt = 0.04 * 1.5 d?/dt = .057 rad/s d?/dt is constant, and since there are 2? radians in one revolution, the period is 2?/.057 = 110 seconds Better check my math; 2 minutes/rev seems like a long...

**Trigonometry**

anything which makes 1-sinx=0

**Math**

Just write the facts as equations: b = g+p p = 12 g = p/2 Now find b+g+p

**Algebra/ Geometry**

?(1.5r)^2 = ?r^2 + 100 9/4 ?r^2 = ?r^2 + 100 5/4 ?r^2 = 100 r^2 = 80/? r = 4?(5/?) so, the original circumference is c = 2?r = 8?(5?)

**Homework Dump**

If you have no ideas on any of these, you clearly have not studied the material yet. When you have some suggested solutions, we can check your work.

**math**

just change all the signs of y. f(x) = -2/3x+2 --> -f(x) = -(-2/3x+2) and so forth

**Geometry**

just as the volume of a rectangular brick is length*width*height, it is also base*height, with the base having area B=length*width, so v = Bh A triangular prism also has volume Bh, where B is the area of the triangular base. try googling prisms and volumes for more discussions...

**Geometry**

well, you haven't said which two dimensions constitute the triangular base. If the triangle has base=15 and height=12, then its area is 90. Then the volume is 90*7 = 630

**Geometry**

v = Bh you know how to figure B -- it's just the area of the triangle, so ...

**math**

So, the total man-days worked in the 14 days is 2*24 + 2*28 + 10*22 = 324 Without knowing how much total work is needed, there's no way to tell how many more days it will take.

**Geometry**

Assuming P is between A and B, then (6+2)/(-2-x) = 3/2 x = -22/3 If B is between A and P, or A is between P and B, other conditions apply, as I'm sure you can figure out.

**Geometry**

The area is bounded by 1/4 of the circle with center at (-8,8) and radius 8. So, it's just r^2 - 1/4 (pi r^2) 64-(1/4)pi*8^2 = 64-16pi

**Math**

-60 is included so, which way is to the right? greater or less?

**Math**

you've been on this site long enough to know that diagrams don't make it here.

**Trigonometry**

the boat has traveled 5 miles. So, if the distance to shore is d, d tan70° - d tan63° = 5

**Trigonometry**

42m

**Algebra**

I assume you are studying the distributive law. So, 3*(x-y) = 3*x - 3*y or, 3x-3y do the other in like wise.

**Math**

speed * time = 500

**math**

A = P(1+r)^t

**maths**

jut note that h/42 = tan 36°

**physics**

The half-life is 3.82 days That means that every time 3.82 days have passed, 1/2 of it is gone. So, starting with 400 nuclei, after 2 days there will be 400(1/2)^(2/3.82) = 278

**Math**

.06x = .20*6

**algebra 1**

(3x-6)(x+4)

**Math**

since 1m = 3.28 ft, the area is 4*5 * 3.28^2 = 215.17 ft^2

**math**

ar^2 = 54 ar^6 = 1/54 r^4 = 1/54^2 r^2 = 1/54 a = 54^2 T5 = ar^4 = 54^2 * 1/54^2 = 1 The sequence is 54^2, 54/?54, 54, ?54, 1, 1/?54, 1/54 ...

**Math**

the marked price should have been .95p, or 19*.05p = 19*4.20 = 79.80

**Math**

I assume that "70percents/dozen" means "70 cents per dozen." If so, he sold 2400 = 200 dozen at that price. So, his % profit is ((200*.70)-100)/100 = 40%

**Math**

since volume scales as the cube of the linear ratio, the small cone has 1/27 the volume of the whole cone. So, the parts' volumes are 5(1/27) and 5(26/27)

**Math**

10/2 (2a+9d) = 20/2 (2a+19d) 20a+90d = 40a+380d 20a+290d = 0 2a+29d = 0 S30 = 30/2 (2a+29d) = 0

**speed**

distance = speed * time, so if Tom's speed is s, his distance was 4s. For Jerry, (4/5)(4s) = 4(s-2) solve for s, and then you can get the distance: 4s

**science (physics)**

assuming constant acceleration from position s(0)=0, s(t) = vt + 1/2 at^2 So, we have s(5)-s(4) = 10 s(10)-s(9) = 30 now just plug in the numbers and you get 5v+25(a/2)-(4v+16(a/2)) = 10 10v+100(a/2)-(9v+81(a/2)) = 30 Now just solve for a and v.

**Geometry**

Take a look at the figure here, and plug in your numbers: http://mathcentral.uregina.ca/QQ/database/QQ.09.07/h/astrogirl1.html

**Math**

12x+30*900 = 42*875

**Math**

1.12c = 6 + 0.88c

**math**

well, x = 5n y = 2n-1 Now just get rid of n.

**math**

x + 2(60-x) = 92

**math**

so, did you graph it? Where does the line cross the x-axis?

**math**

t = 7x t+5 = 4(x+5) so, 7x+5 = 4(x+5)

**College Algebra**

I = k/d^2 so, Id^2 = k is constant So, find d such that 40d^2 = 90*5^2 and subtract 5