Wednesday
February 10, 2016

Posts by Steve

Total # Posts: 37,538

Geometry
if the angle is x , then tan(x) = .284 x = arctan(.284)
February 10, 2016

Math
100/(b+24) what do you get for the other?
February 10, 2016

Math
(1 2/3):(5/4) = (5/3):(5/4) = 4:3
February 10, 2016

math
r^3 = -243/72 = (-9*27)/(9*8) r = -3/2 a(-3/2)^2 = 72 a = 32 S10 = 32(r^10-1)/(r-1) = -11605/16
February 10, 2016

Onto functions
Read the introduction in wikipedia explaining the difference between range and codomain. For example, if g:R->R g(x)=x^2, then the codomain is all of R, but the range (image) is [0,∞) For this problem, g is onto, since both the codomain and the image are [1,∞). ...
February 10, 2016

Cal 2
However, just so you get to use your calculus to analyze the frustrum, just think of it as a stack of thin discs of thickness dx: v = ∫πr^2 dx where r=y=3x v = ∫[3,5] π(3x)^2 dx = 294π Or, as a bunch of nested shells, it gets a bit more complicated, ...
February 10, 2016

math
read amount read rate mrate = rate/12.0 bal = amount * (1+mrate)^4 that last expression might vary, depending on the language: (1+mrate)**4 pow(1+mrate,4)
February 10, 2016

algebra
y-0 = 2(x-0) y = 2x
February 10, 2016

math
Not quite sure how to parse that 2nd sentence, but let's just work with the height of the tower above his eye level. Draw a diagram and review the cot function. You will see that if the height is h, h cot28° - h cot35° = 50 Now find h and add 1.70
February 10, 2016

angle relationships
90° - 48°26'8"
February 9, 2016

Shresta
cosx sinx = √2 cosx sinx = √2 sorry - cannot happen However, cosx-sinx = √2 (1/√2 cosx - 1/√2 sinx) = √2 sin(π/4 + x)
February 9, 2016

Calculus
Hmm. In that case, you need times where both hands are exactly on numbers. So, there are 11 such times, exactly on hours. At 2:00, say if you switch hands the hour hand will be on 12 and the minute hand will be on 2, so the time is 12:10. Now, on a real clock, the hour hand ...
February 9, 2016

Math
9m+6n = 3 8m+6n = 6 subtract and you have m = -3 That means n = 5
February 9, 2016

Math
If you mean quadratic regression, I'd google the topic and read some of the articles. Hard to believe such a complicated process would be on a test under limited time. At any rate, if you do find a quadratic f' = ax^2+bx+c, then clearly f = a/3 x^2 + b/2 x^2 + cx + d ...
February 9, 2016

Math
.84^n = .25
February 9, 2016

math
I assume we are talking about the 1st terms of the sequences. well, shucks, 32=2^5 1*2*4*8*16 too big 1/2 * 1 * 2 * 4 * 8 = 32 a= 1/2 r = 2 S19 = 19/2 (a + 18d) but, a+9d = 2 so, 2a+18d = 4 so, a+18d = 4-a = 7/2 S19 = (19/2)(7/2) = 133/4
February 9, 2016

math
(7+x)/12 = 4
February 9, 2016

Geometry
In fact, it's not drawn here at all. However, opposite angles are equal successive angles are supplementary.
February 9, 2016

programming
well, the hardest part is picking off the digits of the number. That is easily done by taking the remainder when dividing by 10. So, if the number is n, this can be achieved by the following loop: int n,d; d=0; while (n > 0) { d = n%10; #now you have the ones' digit #...
February 9, 2016

math :) website
You're Welcome.
February 9, 2016

math :) website
This website should help you. http://www.purplemath.com/modules/meanmode.htm
February 9, 2016

I NEED HELP WITH THIS. PLZ
https://www.connexus.com/content/media/595718-3162012-80436-AM-754148529.png FOR #1
February 9, 2016

Math
If they start with amounts c and s (in cents), then we are told c+80 = 0.80s s+70 = 1.50c now just solve for c and s.
February 9, 2016

physics
this is discussed here: http://hyperphysics.phy-astr.gsu.edu/hbase/electric/elesph.html
February 9, 2016

salag national high school
There are 5! = 120 ways to arrange 5 flags. Since 2 of them cannot be distinguished from each other, divide that number by 2.
February 9, 2016

math
geez - just plug your numbers into the formula: S11 = 11/2 (2*2+10*3)
February 9, 2016

math
each year the car is worth 90% of its prior value, so 600000*0.9^4 That's some car!! Sure it was not a house or a yacht?
February 9, 2016

GYAN
Until you say how many they lost, no way to tell. However, if you know how many total games they have played, the fraction won will be 13/total then convert that to a percent.
February 9, 2016

phisics
clearly the flight lasted 0.5 seconds. So, how far did it fall in 0.5s? s = 1/2 at^2
February 9, 2016

math
Draw a diagram. If the pole has height h, then h cot36° + h cot42° = 50 h = 20.1 Now, the wires have lengths 20.1/sin36° and 20.1/sin42°
February 9, 2016

Calculus 2
It doesn't really matter which variable is used, since the boundary changes in either direction. Cleverly enough, the hyperbola intersects the two lines at (√(7/2),√14) and (√14,√(7/2). So, a = ∫[0,√(7/2)] (2x)-(x/2) dx + ∫[√...
February 9, 2016

ALGEBRA
one is: 2.00x + 1.50y = 20.00
February 9, 2016

computer programing
assuming that the code being reused is well structured, it will contribute to the structure of the whole program. Plus, if the used code has been tested, it will shorten the development time, since known good code is being used.
February 9, 2016

Calc
Nope. That's way too fast. How long does it take to fall to a height of -250m? 35t - 4.9t^2 = -250 t = 11.56 Now, v = 35 - 9.8t = -78.26
February 9, 2016

Math
well, you could factor out the 2, making it (2±i√10)/7
February 8, 2016

Calculus
Something missing from this answer? http://www.jiskha.com/display.cgi?id=1454557669
February 8, 2016

math
for x miles, you want 70+.40x < 50+.50x 20 < .1x 200 < x so, at 200 miles, A starts to be cheaper.
February 8, 2016

math
0.1x <= 5.00 Suppose pencils cost 10 cents each. If you only have $5.00 to spend, how many pencils can you buy?
February 8, 2016

calculus 1
#2 more properly, °F/mo otherwise, they look good.
February 8, 2016

equation
but you could start with d = 2m
February 8, 2016

equation
what a wimp.
February 8, 2016

calc
what is a negative line? A vertical line means a sudden, probably discontinuous) jump in value.
February 8, 2016

Math
(3/4)(6) = 18/4
February 8, 2016

Math
gals = (gals/min)(min) a = 500m
February 8, 2016

Science
well, 1 square means 3 feet. Other than that, I have no idea how many squares you need. Only one, if you want to draw a 3' distance.
February 8, 2016

Physics
V = k/P That is, VP = k is constant so, you want P such that 15P = (2)(1065)
February 8, 2016

Physics
since time = distance/speed, 1/(2-1) + 1/(2+1) = 1/1 + 1/3 = 4/3 Looks like (D) to me
February 8, 2016

Math
If we let the length of a whole board be 1, then for n boards, we have 2/5 n = 4 n = 10
February 8, 2016

maths
a loss of 10% means that each year the value is 90% of what it was before.
February 8, 2016

Grade 5 math
express all distances in the sam units: 400m = 400m .45km = 450m 40,000mm = 40m Now what do you think?
February 8, 2016

math
floor: 12*10 long walls: 2(12*8) short walls: 2(10*8) Now add 'em up.
February 8, 2016

Math
29.95/1.02 = ?
February 8, 2016

physics
see related questions below
February 8, 2016

Math
1B Can you not tell that by looking at the figure? 2B a square is a rectangle with 4 equal sides. 3B just look at the letters, keeping them in the same order.
February 8, 2016

Math
apparently her notation is ^. for * meaning multiply. Trés strange.
February 8, 2016

math
First, that's pi not pie!!! Just start subtracting 2pi from your angle until the result is between 0 and 2pi. 3pi - 2pi = pi we have a winner!
February 8, 2016

maths
When asking how much one value is than another, you just subtract. If I ask How much bigger 10 is than 3, you do 10-3=7. So, (-39)-(-98) = -39+98 = 59
February 8, 2016

math
well, did you try actually verifying it? (5/8)(-3/5) + (1/16)(-3/5) = -15/40 - 3/80 = -33/80 3/16 - 3/5 = 15/80 - 48/80 = -33/80 I guess your answer is correct.
February 8, 2016

Math
If there are x lbs, each one gets x/3 so x >= 10.5 x/3 >= 3.5
February 8, 2016

Algebra
105 mi/hr = 154 ft/s So, it takes 60.5/154 seconds
February 8, 2016

Math
the independent variable is the one which you can set to whatever you want: in this case, the number of students. Since there is a fixed cost for each student, the cost depends on the number of students.
February 8, 2016

MATH
5x + 4.20(26-x) = 4.80*26
February 8, 2016

MATH
stop posting problems which refer to a pictures we cannot see.
February 8, 2016

math
3^x * 5^x + 1=20 (3*5)^x = 19 15^x = 19 x = log1519
February 8, 2016

Math
hard to say, with no picture to see.
February 8, 2016

Math
area grows as the square of the sides. So, the areas are in the ratio (2/3)^2 = 4/9
February 8, 2016

Math
If you mean of a circle, it is that portion of a circle subtended by a central angle. That is, if two radii are drawn, the sector is the area between them.
February 8, 2016

Maths
(22^3 * 7/8)/(π/6 * .5^3) ≈ 142,353
February 8, 2016

math
p(w) = 7+2w
February 8, 2016

Calculus (double integral) PLEASE HELP!
This exact transformation is discussed on pp 3-5 of http://math.etsu.edu/multicalc/prealpha/Chap4/Chap4-4/printversion.pdf
February 8, 2016

Math
p(t) = 157354 * 2^t
February 8, 2016

math
One way is elimination, where you multiply the equations to enable addition to eliminate one variable: 6x+4y = -36 -6x+15y = -78 now if you add them up you get 19y = -114 Thus, having y, you can now get x from either equation.
February 8, 2016

math
the area of the border is (500)(130)-(500-2*25)(130-2*25) = 29000 cm^2 Now you can find the cost
February 8, 2016

trigonometry
Remember the Pythagorean Theorem? The distance d is d^2 = 200^2 + 60^2
February 7, 2016

Calculus (Jacobian question)
This type of problem is discussed on pages 3-5 at http://math.etsu.edu/multicalc/prealpha/Chap4/Chap4-4/printversion.pdf
February 7, 2016

Math
mass of pure gold would be 5*18*4 cm^3 * 19.3 g/cm^3 = 6948g so, what do you think?
February 7, 2016

calculus
∫ x^3/√(3x^2-5) dx x = √(5/3) secθ 3x^2-5 = 5tan^2θ dx = √(5/3) secθ tanθ dθ and the integral becomes ∫ √(5/3)^3 sec^3θ/(√5 tanθ) √(5/3) secθ tanθ dθ = 5/9 √5 ∫sec^4&#...
February 7, 2016

physics
oops. the horizontal speed is 33.437 cos20° make that fix...
February 7, 2016

physics
h(t) = vt - 1/2 g t^2 3.5v - 4.9*3.5^2 = -20 v = 11.436 That v is the vertical speed at takeoff. So, the entire initial speed is 11.436/sin20° = 33.437 Use that speed and d = vt to get the horizontal distance traveled. d = 33.437 * 3.5 = 117.028
February 7, 2016

Precalculus
Huh? Forget your Algebra I? Anyway, just type in your function at wolframalpha.com
February 7, 2016

Trigonometry
Draw a diagram, and you will see that x cot14° + x cot18° = 55 x = 55/(cot14° + cot18°)
February 7, 2016

math
.42
February 7, 2016

Algebra
u = kp^3/d
February 7, 2016

Algebra
add up the value of the parts: 8.40x + 14.70(70-x) = 14.61*70 Expect a value of nearly zero for x, since the price of the mix is very close to the price of the Mexican coffee.
February 7, 2016

Calculus
The paraboloids intersect along an ellipse 3x^2+2y^2 = 6 So, the volume is (using symmetry) v = 4∫[0,√2] ∫[0,√((6-3x^2)/2)] (6-x^2-y^2)-(2x^2+y^2) dy dx = 3π√6
February 7, 2016

math
you are right
February 7, 2016

Math
You are correct.
February 7, 2016

Numericals
v = √2as = √(2*9.8*15) = 17.146 m/s Since the ball's energy PE = mgh, if it loses 40% of its energy, it will lose 40% of its height, so it will bounce to 9 m. Or, since PE becomes KE just before impact, KE = 1/2 mv^2 The rebound velocity will be .6 * 1/2 m*17....
February 7, 2016

calculus
see related questions below.
February 7, 2016

radicals
just multiply roots like anything else. If a square root contains a perfect square, like 16 or 49, you can factor the 4 or 7 out of the root. For this problem, √8(√(9ab)/√(3b) + √(27a)) 2√2 (√(9ab/3b) + 3√(3a)) 2√2 (√(3a...
February 7, 2016

calculus
a = (90-30)/10 = 6 km/hr-s s = 1/2 at^2 = 3 km/hr-s * (10s)^2 = 300 km-s/hr = 300 km-s/hr * 1hr/3600s = 300/3600 km = 1/12 km or, since you want to use calculus, a = 6km/hr-s = 6km/hr-s * 1hr/3600s = 1/600 km/s^2 so, a(t) = 1/600 v(t) = 1/600 t s(t) = 1/1200 t^2 s(10) = 100/...
February 7, 2016

math
if compound interest, 400(1+r)^4 = 480 (1+r)^4 = 1.2 r = .0466 Is your new r (r + .02)=.0666 or is it 9*1.02 = .0475 ?? Do a similar calculation if simple interest.
February 7, 2016

Math
f(x) = √(x-2) You know that the domain of √x is x>=0. So, you need x-2 >= 0 Not too hard, eh?
February 6, 2016

maths
well, sin(x) = 125/250 = 1/2 look familiar?
February 6, 2016

Maths
If you draw a careful diagram, you will see that the altitude is 240cm between the bases. Using similar triangles, you can see that if the pyramid were not chopped off, its height would be 320/3. So, the missing part is a pyramid of base side 80 and height 400/3. Now just work...
February 6, 2016

Linear Algebra
First, be sure you understand a matrix null space. Google is your friend. Te null space is all vectors x such that xA = 0 I'm having a hard time understanding A[1, 1, 1]^t = [2, 3]^t = A[2, 3, 4]^t How can they all be equal?
February 6, 2016

Calculus
Just integrate a = ∫[-1,0] (13-5x)/3 - (-6x) dx + ∫[0,2] (13-5x)/3 - x/2 dx = 13/6 + 13/3 = 13/2 Or The distance from (0,0) to (1,2) is √5. Let that be the base of the triangle. The altitude is the distance from (-1,6) to y=x/2 (or -x+2y+0=0) is |1+12|/√...
February 6, 2016

Physics 30
see Coulomb's law.
February 6, 2016

Physics 30
since only one current is given, I'll assume the R are in series E = IR, so 22 = .012(27+R)
February 6, 2016

Physics 30
come on, that's ohm, not omega. Omega is just the symbol used for the unit. 1A = 1C/s P = I^2R = (10/5)^2 * 25 = 100 W energy = power * time
February 6, 2016

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