Tuesday

May 5, 2015

May 5, 2015

Total # Posts: 31,059

**Calculus**

a = πr^2 da/dt = 2πr dr/dt So, plug in your numbers. When a = 4π, r=2, so 2 = 2π*2 dr/dt dr/dt = 1/(2π) miles/day
*March 29, 2015*

**Math**

yeah - compound or simple!
*March 29, 2015*

**Math**

the problem will tell you which it is. Although, if it neglects to say the compounding period, it is most likely simple interest.
*March 29, 2015*

**Algebra 1**

thank you
*March 29, 2015*

**Algebra 1**

If the leg of length 11 is adjacent to angle a, you are correct.
*March 29, 2015*

**Algebra 1**

In a right triangle c=90 degrees a=52 degrees b = 38 degrees the base length =11 What is the hypotenuse length? a-6.8 b-8.7 c-14.0 d-17.9 my answer is 17.9 d
*March 29, 2015*

**Algebra 1**

x=1 does satisfy the equation.
*March 29, 2015*

**Algebra 1**

Solve for x sq root 2x+3= sq root 6x-1 a-1 b-2 c-3 dsq root 6 My answer is a = 1
*March 29, 2015*

**Algebra 1**

correct
*March 29, 2015*

**Algebra 1**

A right triangles hypotenuse is 20 cm long. What is themlength of the side opposite a 60 degree angle? a- 40 b- 18.5 c- 20 d- 17.3 My answer is 17.3
*March 29, 2015*

**Algebra 1**

In a right triangle the height = 54 (ba) The hypotenuse is 90 (ac) and the base ism 72 (bc). What is the value of cosC? a-.5 b- .6 c- .8 d- .9 My answer is .8 72/90
*March 29, 2015*

**Geometry**

2(w + w+40) = 500
*March 29, 2015*

**integral calculus**

just apply the power rule to each term ∫ x^n dx = 1/(n+1) x^(n+1) so, ∫ x^4 dx = 1/5 x^5 and similarly for the other terms
*March 29, 2015*

**math**

each face is a triangle with base 8 and altitude 22
*March 29, 2015*

**ALGEBRA**

clearly the compound inequality is an and problem. As for absolute value problems, think of the shape of the graph. It is a V shape. So, if |f(x)| < c, you have one interval, below the line y=c. If |f(x)| > c, then you have the intervals outside the V, making it an or ...
*March 29, 2015*

**maths**

if they are in series, then R = 2+3+r If they are in parallel, then 1/R = 1/2 + 1/3 + 1/r
*March 29, 2015*

**math**

9-m^2 = (3-m)(3+m) So, the (3-m) factors cancel, and you have (3+m) in the top. Not sure just what the other stuff means; your use of numbers and carets is inconsistent. Just recall that u^n/u^m = u^(n-m) whatever u is.
*March 29, 2015*

**Math**

the distance z between you and Jonas after t seconds is z^2 = (60-2t)^2 + (10t)^2 For the box, we know xyz = 500000 since y=2x, 2x^2z = 500000 x^2z = 250000 So, z = 250000/x^2 c(x) = (x)(2x)(3) + (6x)(250000/x^2)(4) + (x)(2x)(5) = 16x^2 + 6000000/x Now just do your minimum stuff.
*March 28, 2015*

**Math**

I went back and checked my figures and I think it should be a t sq root 26
*March 28, 2015*

**Math**

A playground is shaped like a rectangle with a width 5 times it's length (t). What is the simplified expression for the distance between opposite corners of the playground? a- tsq root 26 b- 5t c- 26t squared d- 6t my answer is d 5t 5t+t =x x=6t
*March 28, 2015*

**Math**

Simplify 6/sq root 3 +2 My answer is 12 - 6 sq root 3
*March 28, 2015*

**Math**

thank you
*March 28, 2015*

**Math**

A surfer drives his dune buggy out into the sand dunes.He follows his compass 10 miles due north and then turns due west. If he ends up approximately 35 miles from where he started how far west did he travel? a- 10 miles b- 25 miles c- 33.5 miles d- 35 miles My answer is c 33....
*March 28, 2015*

**Math--MS SUE!**

#1 24 #2 46 #3 70
*March 28, 2015*

**Math**

Good job, Reiny. I keep seeing 3^√ being used as cube root, so maybe I was way off. In any case, the problem is solved.
*March 28, 2015*

**Math**

let f(x) = x^3 - 7 so f(∛7) = 0 See http://keisan.casio.com/exec/system/1244946907 just enter your function, its derivative, and initial guess.
*March 28, 2015*

**Earth Space Science**

you are correct.
*March 28, 2015*

**statistics**

so, do you have a table of NBA players' heights? If so, just do what the exercise says.
*March 28, 2015*

**Math**

I get XB=6 How far do you get? Hint: parallel lines indicate similar triangles.
*March 28, 2015*

**Trigonometry**

Usage differs, but one of them is the single value -π/3, and the other is -π/3+nπ check your text to see what is expected of you.
*March 28, 2015*

**Trigonometry**

just factor the first one, then there will be two values between 0 and 2π, and all multiples of 2π added thereto. 2sin^2(x)-5 sin(x)-3=0 (2sinx+1)(sinx-3) = 0 sinx = -1/2 sinx = 3 (not a valid solution) The other is already factored: (cos(x)-((√2)/2))(sec(x)-1...
*March 28, 2015*

**Trigonometry**

tan(-π/4) = -1 so, θ = -π/4 + nπ sin(π/6) = 1/2, so θ/2 = π/6,5π/6,... θ = π/3, 5π/3, ... = π/3 + 4nπ, 5π/3 + 4nπ
*March 28, 2015*

**Trigonometry**

(2sinx-√3)(2sinx+√3) = 0 sinx = ±√3/2 x = π/3, 2π/3, 4π/3, 5π/3 cos(3x) = -1 so 3x = π,3π,5π x = π/3, π, 5π/3
*March 28, 2015*

**Math**

my answer is D
*March 28, 2015*

**Math**

A gardener is mowing a 20 by 40 yard rectangular pasture using a rectangular pattern. He mows from one corner of the pasture to the corner diagonally opposite. What is the length of this pass with the mower? Give your answer in simplified ,form. a- 10 sq root 20 b- 20 sq root ...
*March 28, 2015*

**math**

2x*5x = 40 So, find x, and then 5x.
*March 27, 2015*

**math**

f(x) = 2(x-1)^2 - 7 So, if we restrict the domain to x>1 or x<1 we can find an inverse I expect you can turn that info into an interval . . .
*March 27, 2015*

**math**

Since referring you to the related questions seems to do no good, here it is again: f(x) = cx/(2x+3) f(f) = cf/(2f+3) = c[cx/(2x+3)]/(2[cx/(2x+3)]+3) = c^2x/(2(c+3)x+9) So, if c^2x/(2(c+3)x+9) = x, c^2x = 2(c+3)x^2 + 9x 2(c+3)x^2 + (9-c^2)x = 0 x(2c+6+9-c^2) = 0 x(15+2c-c^2...
*March 27, 2015*

**math**

Looks to me like g*62 + (75-g)*56 = 75*58 Or, since we're looking for the number of boys, not girls, 56b + 62(75-b) = 58*75
*March 27, 2015*

**Math**

thank you
*March 27, 2015*

**Math**

my answer is 5m
*March 27, 2015*

**Math**

Tasha is planning an expansion of a square flower garden in a city park. If each side of the original garden is increased by 7m the new total area will be 144m^2. Find the length of each side of the original garden.
*March 27, 2015*

**Math**

What is the value of c so that y=x^2+15x+c is a perfect square trinomial?
*March 27, 2015*

**Algebra 1**

Use the graph of f(x) to find the solutions to the equation f(x)=0 a-2 -10 & 2 b_ 2 10 & -2 c- 1 10 d- no solutions
*March 27, 2015*

**Algebra 1**

thank you
*March 27, 2015*

**Algebra 1**

a boulder is thrown launched into the air with an upward velocity of 184 ft per second. Its height h in feet after t seconds is given by the function h(t)=-16t^2 +184t+6. How long does it take the boulder to reach its maximum height? What is the boulder maximum height? a- 11.6...
*March 27, 2015*

**Algebra 1**

Thank you very much at 68 trying to help grandson I'm stretching a bit to when I took this
*March 27, 2015*

**Algebra 1**

so it would be 22 ft after 1 second
*March 27, 2015*

**Algebra 1**

a ball is thrown into the air with an upward velocity of 32 ft per second. Its height h in feet after t seconds is given by the function h(t)=-16t^2 +32t+6. How long does it take the ball to reach its maximum height? What is the balls maximum height? a- 22 ft 1.0 second b- 22 ...
*March 27, 2015*

**Math**

well, just multiply them. If you get the identity matrix, they are inverses Looks like we have a winner! http://www.wolframalpha.com/input/?i=%7B%7B1%2C1%2C1%7D%2C%7B3%2C5%2C4%7D%2C%7B0%2C-1%2C0%7D%7D*%7B%7B4%2C-1%2C-1%7D%2C%7B0%2C0%2C-1%7D%2C%7B-3%2C1%2C2%7D%7D
*March 27, 2015*

**Algebra 1**

244 was on the wrong problem - this one was 0 sorry
*March 27, 2015*

**Algebra 1**

review the discriminant. If it is positive, there are two real roots. In this case, b^2-4ac = 0, so there is but one root. -8x^2-8x-2 = -2(2x+1)^2 How ever did you come up with a discriminant of 244?
*March 27, 2015*

**Algebra 1**

I figured the discriminant at 244 so infinite?
*March 27, 2015*

**Algebra 1**

How many real number solutions does the equation have? -8x^2-8-2=0 o solutions 1 2 infinitely many I get -1/2 so would it be 2?
*March 27, 2015*

**Algebra 1**

thank you
*March 27, 2015*

**Algebra 1**

A physics student stands on top of a hill that has an elevation of 56 meters. He throws a rock and it goes up into the air and then falls past him and lands on the ground below. The path of the rock can be modeled by the equation - y=-0.04x^2+1.3x+56 where x is the horizontal ...
*March 27, 2015*

**Algebra 1**

your right sorry y=-0.04x^2+8.3x+4.3
*March 27, 2015*

**Algebra 1**

A model rocket is launched from a roof into a large field. The path of the rocket can be modeled by the equation- y= -0.04x^2+8.3x,where x is the horizontal distance, in meters, from the starting point on the roof and y is the height, in meters of the rocket above ground. How ...
*March 27, 2015*

**Algebra**

You can also solve it without finding the value of k. Since xy is constant, 150y = 4*300
*March 27, 2015*

**vector algebra**

your operations make no sense u.v is a scalar, so (u.v)xv is undefined naturally, vxv=0, so u.vxv = 0 if u is a vector, what does u^2 mean?
*March 27, 2015*

**ALgebra**

see related question below
*March 27, 2015*

**math**

he was a midget.
*March 27, 2015*

**math**

(30 * 3 3/4)/20 = 5 5/8 so, how many whole bolts?
*March 27, 2015*

**programming concepts**

to find the average, just add up all the numbers and divide by how many there are. That means you have to count them as you read them.
*March 27, 2015*

**Math**

cool. Look. We don't mind helping find answers, but at least can we expect not to have to provide the question as well?
*March 26, 2015*

**Math Venn Diagram**

Did you make a Venn diagram yet? Put any numbers in it? Start with the 4 in the middle. Then work your way out from there.
*March 26, 2015*

**Math**

4*6*(5-x) = 2*4*6* 5-x = 2 x = 3
*March 26, 2015*

**Math**

9*pi*1.2 units/min
*March 26, 2015*

**geometry**

yep. so stipulated.
*March 26, 2015*

**Math**

9*3.77 units/min
*March 26, 2015*

**pre algebra**

well, how much after one payment?
*March 26, 2015*

**Physics**

If A is moving in the positive direction, then we must have zero total momentum before and after the collision: 10(15) + m(-5) = 0
*March 26, 2015*

**math**

well, if the original radius is r, we have π(r+1)^1 = 100π Or, just note that it's obvious that a radius of 10 gives an area of 100π, so the original radius was 9.
*March 26, 2015*

**Math 115**

You have any thoughts on any of these?
*March 26, 2015*

**Math 115**

If the cheap sides are x, and the expensive side is y, then xy = 320 c(x) = 6*2x + 6y + 14y = 12x+20y = 12x + 20(320/x) c'(x) = 12 - 6400/x^2 minimum cost is at x = 80/√12 ≈ 23 So, the area is roughly 23 by 14 (That's 322 ft^2)
*March 26, 2015*

**Math 115**

P = R-C that will be a parabola. Find its vertex.
*March 26, 2015*

**Math**

Look. If I said I had to pick 10 apples, but I only had 7 so far, how would you decide the number I still needed? Don't let the fractions scare you. They're just numbers.
*March 26, 2015*

**Math**

subtract what he has from the total.
*March 26, 2015*

**math**

f(x) = cx/(2x+3) f(f) = cf/(2f+3) = c[cx/(2x+3)]/(2[cx/(2x+3)]+3) = c^2x/(2(c+3)x+9) So, if c^2x/(2(c+3)x+9) = x, c^2x = 2(c+3)x^2 + 9x 2(c+3)x^2 + (9-c^2)x = 0 x(2c+6+9-c^2) = 0 x(15+2c-c^2) = 0 x(5c-1)(3c+1) = 0 So, c = 1/5 or c = -1/3
*March 26, 2015*

**Algebra**

f(x) = 2(x-1)^2 - 7 So, if we restrict the domain to x>1 or x<1 we can find an inverse
*March 26, 2015*

**math**

h = 1/√x h^2 = 1/x x = 1/h^2 so, h^-1(x) = 1/x^2 h^-1(4) = 1/16
*March 26, 2015*

**algebra**

since g(x) is a parabola, there are two values of x for every value of g. So, there is no inverse. However, if you pick a single branch of the parabola (that is, you restrict the domain), there is an inverse.
*March 26, 2015*

**Math**

Convert 22 miles to yards. Use a proportion to solve. Show your work. Where do I start with this problem?
*March 26, 2015*

**calc**

f is a polynomial, so it is continuous and differentiable f(4) = f(0) = 8, so that's ok So, you want c where f'(c) = 0 That means you need 3c^2 - 2c - 12 = 0 c = 2.361 The other value is not in [0,4]
*March 26, 2015*

**Math**

starting from M, you go 74 SE and 42 W That is (52.33,-52.33) + (-42,0) = (10.33,-52.33) tanθ = -52.33/10.33 = -78.8° So, the bearing is 168.8° or E 78.8° S or S 11.2° E
*March 26, 2015*

**5th grade math**

80 <= 1.22n <= 85 divide through by 1.22 and you get 65.57 <= n <= 69.67 If you want only integer values for n, then that would be any of 66,67,68,69
*March 26, 2015*

**geometry**

not sure how I'd do it without trig. Any clever geometric relationships that make it easy?
*March 26, 2015*

**geometry**

in triangle PQS. sinP/9 = sinQ/8 = sinS/5 So, you can find angle P Now, using the law of cosines in triangle PRT RT^2 = 10^2 + 16^2 - 2*10*16*cos(P)
*March 26, 2015*

**calculus**

p(8) = 1536 p(4) = 192 so, avg v is (1536-192)/(8-4) = 336 p'(t) = 9t^2 so, you want 9c^2 = 336
*March 26, 2015*

**7th grade math (probability)**

They all look good to me.
*March 26, 2015*

**math**

Huh? You said above what the vertex is. as always, it is at t = -b/2a It is not at t=3, but very close. Probably good enough.
*March 26, 2015*

**math**

clearly there is an x-intercept somewhere just beyond 6. See how the height is descending. Since the given h values do not show an obvious symmetry, it is not immediately clear where the vertex is. However, since h(0) = 0, if h(t) = at^2 + bt + c c = 0, so h(t) = at^2 + bt ...
*March 26, 2015*

**math**

try writing fractions like this: 2/3 + x/4 = 4/7
*March 26, 2015*

**Algebra**

two real roots
*March 26, 2015*

**Math**

well, just work from the inside out 2/3 - 1/3 = 1/3 so, what you have without the brackets is 1/3 * 5/8 = 5/24
*March 26, 2015*

**Math**

1 yd = 3 ft (1 yd)^3 = (3 ft)^3 = 27 ft^3
*March 26, 2015*

**Algebra 1**

(66-6)/6 = 10 (77-7)/7 = 10
*March 26, 2015*

**^math^**

√(19-4√21) since 21 = 19+2, I'd check (2-√21)^2 = 4-4√21+21 nope (1-2√21)^2 = 1-4√21+42 nope (2√3-√7)^2 = 12-4√21+7 aha!
*March 26, 2015*

**MATH**

.08x - .05(36000-x) = 2750
*March 26, 2015*

**algebra**

simple interest, yes compound interest, no
*March 26, 2015*