# Posts by STEVE

Total # Posts: 51,753

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

multivariate calculus
I've done a couple of these for you now. Where do you get stuck? What do you have so far? Doing the partials can be tedious, but not difficult. You can get some help here, for example, to verify your work: http://www.wolframalpha.com/input/?i=d%5E2%2Fdx%5E2+ln(x%5E2+%2B+y%...

Math
since the height:shadow ratio is the same, 64/30 = h/25

math
well, 2+5=7 so, what do you think? More algebraically, if there are 2x dogs and 5x cats, 2x+5x = 14 solve for x, and then you can tell how many animals are there.

Math
There are 4 rectangular faces, each 7x13

math
geez - impatient much?

Science
mine, too

Science
well 1 million would provide 1000000/24000 = 41.7 mg

Science
so, how many nematocysts are there? divide by 24000 to see how many grams

Science
B & D look good to me

math
Can't say I care much for your text formatting. Since you seem to be dealing with fractions, I assume you meant to say R = 3/x + 9/y So, just plug in your numbers and solve for x: 7 = 3/x + 9/6 If I got the function wrong, just fix it and plug in the numbers to get ready ...

math
just subtract the picture from the total area: (40+15)(50+15) - 40*50

Calculus
well since the fraction approaches 1/0, clearly it will approach either +? or -? So, just check the denominator to see whether it is positive or negative. a) x->2+ means x > 2. So, x^2 > 4 and the limit is +? similarly for the others.

Math
m = 3d m-5 + d-5 = 50

Math
a - x/2 = 12 a + x/2 = 2x x = 2x-12 x = 12 finish it off

Math
j+k+b = 390 j = 5b k = 3/4 j now just solve for k.

Math (Integrals) (Volume of Revolution Setup)
looks good to me

Math Tangent Graph
the graph of tan(x) goes through (0,0) and has asymptotes at -?/2 and ?/2, for a period of ?. This graph also goes through (0,0) but its asymptote is at -?/6, for a period of ?/3. So, it is the graph of tan(3x) Or, note that instead of a single period in [-?,0] it has 3 periods.

Algebra
You have some funky formatting there. I read it as f(x) = 8*3^(x-2)+2 but it doesn't really matter what f(x) is. Stretching by a factor 3 just means that g(x) = 3*f(x)

physics
scroll down a bit here, and you can figure it out. https://en.wikipedia.org/wiki/Trajectory

Math
surely you can see that 0 represents the year Gabe was born. since Gabe was 14 in 2002, you can easily figure out the year that he was born.

Math
correct

Math
geez - just get out a pencil and draw the number line. Start at 0. Move right 10 and then left 11 where are you?

maths
well, there are 7 1/2 circles. They represent 15 goals, so 15/(7 1/2) = ?

Algebra (Ms.Sue!!)
if you add 5 to each value, you add 5 to the mean and median. The range is unaffected. if you multiply by 6, the mean and median get multiplied by 6, and so does the range. Review these topics in your text or online. The definition of these items will show how they are ...

Math
well, .22x = 209

Math
quite a difference in your posts. 2x * 9x^(y^9)) = 18x^(y^9+1) Now, taking the derivative of u^v is a combination of d/dx a^v = lna a^v dv/dx d/dx u^n = n u^(n-1) du/dx d/dx u^v = v u^(v-1) u' + lnu u^v v' Since we have u=x, and v=y^9+1, taking d/dx, we get (y^9+1) x^(...

Calculus
why all those messy words? You appear to be saying f(x) = 3 for -3 <= x < 0 -x+3 for 0 <= x <= 6 -3 for 6 < x <= 9 g is increasing where f is positive: [-2,0)U(3,6] g(x) = ?[-2,0] 3 dt + ?[0,x] -t+3 dt = 6 + (-x^2/2 + 3x)+3 for 0<=t<=6

Physics
F = ma now just plug in your numbers.

calculus
s = ?[0,?] ?((2t)^2+(t cost)^2+(t sint)^2) dt = ?[0,?] ?(4t^2+t^2) dt = ?5/2 ?^2

Math Probability
I agree

geometry hhhheeeelllllpppppp
there are two triangular bases of area (1/2)*3*2.6 there are three rectangular faces. One has area 12*3 the other two have length 12, but we do not know the other two sides of the triangle...

calculus
well, you have tanz = r^2 tan2? z = arctan(r^2 tan2?) ?z/?r = (2r tan2?)/((r^2 tan2?)^2+1) ?z/?? = (2r^2 sec^2(2?))/((r^2 tan2?)^2+1) the second partials get a bit messy, but you can get them here: http://www.wolframalpha.com/input/?i=d%5E2%2Fdr%5E2+arctan(r%5E2+tan2%CE%B8) ...

calculus
just crank it out ?u/?x = 2x/(x^2+y^2) ?u/?y = 2y/(x^2+y^2 ?v/?x = -2y/(x^2+y^2) ?v/?y = 2x/(x^2+y^2

MATH
the link is missing a domain name, such as http://pictures.com/...

math
16 2/3% = 1/6 1/6 * 9 = ...

math
12* 5/3 = 5 * 12/3 = ...

maths

maths

maths
this is the same as cos30/sin30 + sin30*cot30 = cot30(1+sin30) = ?3 (1+1/2) = 3?3/2

maths
These are standard angles, whose functions you would do well to learn Cos45+sin60-tan30 = 1/?2 + ?3/2 - 1/?3 = (3?2 + ?3)/6

maths
well, (1+cot²x) = csc²x

Geometry
there are many possible line segments drawn from a to bc

Maths
301 They all leave remainder

Algebra
what's the trouble? They say S = ?(30fL) just plug in your numbers and solve for L

Algebra
If the painting has length x and height y, and the frame has width w, then we have x+2w = 10 y+2w = 8 x^2+y^2 = 100 Now just solve for w

Math
I get 104. What do you get?

Math
try using <= for "less than or equal" "under 12" means "less than 12" so, what do you think?

Math
n > 130-87

Math Check! #3
yeah, but how does that relate to choosing 4 players from a group of 8?

Math Check! #3
Hmmm. How did you get 336? This is just a "choose 4 of 8" combination. 336 = P(8,3) How does that relate to this problem. I suspect you just guessed.

maths
not sure what -< and +< mean

Math
2/(3/4) = x/30

Algebra2
Thank you

Algebra2
The water level varies from 12 inches at low tide to 52 inches at high tide. Low tide occurs at 9:15 am. High tide occurs at 3:30 pm. What is a cosine function that models the variation in inches above and below the water level as a function of time and hours since 9:15 am? ...

Geometry
correct

Algebra2
The function f(theta) and g (theta) are sine functions where f(0)=g(0)=0. The amplitude of f (theta) is twice the amplitude of g(theta). The period of f(theta) is one-half the period of g(theta). If g (theta) has a period of 2pi and fpi/4=4. Write the function rule for g(theta...

MATH
since you give no indications of any side lengths, it's kinda hard for us to say, right? and besides, area is in cm^2, dontcha know

Algebra2
thank you

Algebra2
for which value of theta is tan theta equal to sin theta? My answer is pi

math
42.75*1.18

Math
if you mean the angle is 20°, then the radius r of the circle can be found using' 5/r = sin10° Now you know r, so you can find the area of the circle...

chemistry
how many moles in 5.3g? Molarity is moles/liter

Math
since xy=48 for each pair, B is correct.

Algebra2
Thank you

Algebra2
cos?+1 = 0 cot(?/2) = 0

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