Tuesday

September 27, 2016
Total # Posts: 44,122

**Maths**

2 1/6 - 1 1/3 = 13/6 - 8/6 ...

*September 25, 2016*

**math**

195 is 65% of 300, not of 3000 Anyway, that's not the question. 65% are apples 25% are pears So, 40% difference, means .40*3000 = 1200 more apples than pears

*September 25, 2016*

**maths**

tanA + 4/tanA = 4 (tan^2A+4)/tanA = 4 tan^2A - 4tanA + 4 = 0 (tanA-2)^2 = 0 tanA = 2 ...

*September 25, 2016*

**Science**

(65-16)km/hr / 10min = 4.9 (km/hr)/min now, 1 km/hr = 1000m/3600s, so now you have (4.9 * 1000/3600 m/s) / 60s = 4.9*1000 / 60*3600 m/s^2

*September 25, 2016*

**Chemistry**

Similar question to http://www.jiskha.com/display.cgi?id=1474753951 "If that 22.33g sample of calcium chloride was dissolved in 1000.0g of water, with both substances originally at 25.0C, what would be the final temperature of the solution be? Assume no loss of heat to ...

*September 24, 2016*

**Physics**

The range is v^2/g sin2θ. So, solve for θ in 15000^2/16 sin2θ = 1200 * 5280 for the time, use θ to find when h=0: h(t) = 15000sinθ t - 8t^2 = 0

*September 24, 2016*

**Applications of functions**

y=20-x

*September 24, 2016*

**Precalculus**

No idea of your diagram, but this illustration is found in many places. Probably even in your own textbook. Surely online.

*September 24, 2016*

**Math/Chem**

yes

*September 24, 2016*

**Physics**

You need to know how far each moved during the jump. You know the speeds, so you just need to know how much time the jump took: v sinθ t - 4.9t^2 = 0 Solve for t and use it to get the distances.

*September 24, 2016*

**Physics**

google four point charges field at midpoint and you will find many similar problems. Just tweak the numbers.

*September 24, 2016*

**Physics**

you don't really need to write in the arrows. Anyone familiar with the topic knows these are vector quantities. Torque = p x E you have p, so how is E defined in terms of Q and r?

*September 24, 2016*

**science**

momentum = mass * velocity

*September 24, 2016*

**Maths**

Hmmm. I'd say 63 64 61

*September 24, 2016*

**Math**

mark your point: 8 On the number line, "less than" means "to the left of" So, in this case, that means toward the origin, and to infinity and beyond ...

*September 24, 2016*

**Spanish**

I'm sure you can, after a little research.

*September 24, 2016*

**Math**

0 <= 2 is true 0 is less than 2 0 is not equal to 2 zero IS less than OR equal to 2 If you say that today is hot or humid, it is true even if it is not humid, as long as it is hot.

*September 24, 2016*

**Physics**

How long were you in the air? v sinθ t - 4.9t^2 = 0 So, the dog's speed is 1.72/t This assumes that at t=0 you and the dog were in (approximately) the same spot.

*September 24, 2016*

**Chemistry**

with constant V, P/T is constant. So, what is P/T at stp? Now substitute in your new P.

*September 24, 2016*

**Math**

ok on both

*September 24, 2016*

**Physics**

the distance Chloe jumps is v^2/g sin2θ Now you know her horizontal speed: v sinθ how long she was in the air: v sinθ t - 4.9t^2 = 0 you can figure how far they both moved in that time.

*September 24, 2016*

**Physics**

Starting at the top of the ramp, the rider's height is h(t) = 1.60 sin23° t - 4.9t^2 So, find t when h=0 The rider's velocity when he hits the ground is Vx = 1.60 cos23° Vy = 1.60 sin23° - 9.8t So, the speed v at time t is found using v^2 = Vx^2 + Vy^2

*September 24, 2016*

**maths**

google is your friend: (a) https://answers.yahoo.com/question/index?qid=20131112055820AAxrUAf (b),(c) Check out Riccati equations y' = y^2 + q(x)y + p(x)

*September 24, 2016*

**Maths Percentage**

22/24 * 100 = ?

*September 24, 2016*

**Math**

If the length of AB is x, then AP = 2x/5 AQ = 3x/7 PQ = AQ-AP = 3x/7 - 2x/5 = 2 Now just solve for x

*September 24, 2016*

**maths**

infinitely many. Any point on the x-axis will do.

*September 24, 2016*

**math**

geez. How many ways are there to add 18 + 16?

*September 24, 2016*

**Physics**

340m/s * 2s = 680m

*September 24, 2016*

**Math**

48/(5+(11-8)) - 7

*September 24, 2016*

**Maths - Woe Is Me!**

fix the typos And what does p>+-24 mean. I get that +- means ±, but what does p>±24 mean? Also what are you supposed to do with 18x^2+2px+32 ?? factor it? solve for the roots? find p such that it is a perfect square? what, oh, what? Wooooeeee is meeee!!

*September 24, 2016*

**Geometry**

You know that AP+PQ+QB = a Now, AP = 2PQ = 2BQ That means that PQ = QB and that gives us 2PQ + PQ + PQ = a 4PQ = a PQ = a/4 Let M be the midpoint of QB Let N be the midpoint of AP AM = AP+PQ+ QB/2 = a/2 + a/4 + a/8 = 7a/8 NM = AP/2 + PQ + QB/2 = a/4 +a/4 + a/8 = 5a/8 Draw and ...

*September 24, 2016*

**Geometry**

first, recall that supplementary means they add to 180. So, now you know that A) The two angles are x and x-40 x-40 + x = 180 B) The two angles are 5x and 4x. So, 5x+4x = 180 So, just solve for x, and then you can work out the angles.

*September 24, 2016*

**Trigonometry**

see related questions below google can also help out

*September 24, 2016*

**maths~log**

just for ease of readability, let's say u = log5x v = log3y Then we have 2u+3v=8 6u+2v=2 This has the solution u = -5/7 v = 22/7 Unusual for a problem of this kind, but anyway... log5x = -5/7, so x = 5^(-5/7) log3y = 22/7, so y = 3^(22/7)

*September 24, 2016*

**maths**

I think your sum-to-product formulas will make this just drop out easily.

*September 24, 2016*

**Maths**

AB^2 + BC^2 = AC^2 1 + 1 = 2

*September 24, 2016*

**Maths**

assuming this is an isosceles triangle, I'd say they are both (180-65)/2

*September 24, 2016*

**math**

6 1/2 + 7 2/3 = 6 3/6 + 7 4/6 = ...

*September 24, 2016*

**Algebra**

plug in your data at http://www.gregthatcher.com/Mathematics/GaussJordan.aspx for the details, and confirmation of your answer >wink wink<

*September 24, 2016*

**Math**

DNE means Does Not Exist, so (a) is the choice of choice.

*September 23, 2016*

**Physics**

the range R = v^2/g sin2θ Now just plug in your values

*September 23, 2016*

**Chemistry**

25/800 = 1/32 = 1/2^5 so, it will take 5 half-lives

*September 23, 2016*

**Math**

Try plugging in you numbers here and see whether it is the same. The range is R = v^2/g sin2θ

*September 23, 2016*

**Math**

so, what do you get?

*September 23, 2016*

**Math**

√n is defined only for n>=0 So, the domain of √(2x+1) is (2x+1)>=0, or x >= -1/2 similarly for the other. There is always a domain.

*September 23, 2016*

**Math**

so, after t years, it is 41250 * 1.02^t

*September 23, 2016*

**Physics**

F = ma = 0.39 * 930√2

*September 23, 2016*

**Math , trigonometry**

h/20 = tan(47)

*September 23, 2016*

**physics**

F=ma plug in your numbers and evaluate a. Watch the units.

*September 23, 2016*

**Newtons Cooling Method**

-1.002 ≈ 1, so let's use T(t) = -53e^-t + 89.50 = 85.25 53e^-t = 0.25 e^-t = .004717 t = -ln .004717 = 5.3566

*September 23, 2016*

**math**

−2(x+2/3)+1=5 −2(x+2/3) = 4 x + 2/3 = -2 ...

*September 23, 2016*

**ODE Piecewise**

y'-y = 1: y = ce^x - 1 for 0<=x<=1 y'-y = -1: y = ce^x + 1 for x>1 y(0) = 1 means c=2, so y = 2e^x - 1 for 0<=x<=1 If we want y to be continuous, then since y(1) = 2e-1, y = (2 - 2/e)e^x + 1 for x>1 Thus, y(2) = (2 - 2/e)e^2 + 1 = 2e^2-2e+1

*September 23, 2016*

**Engineering Math**

Start with Newton's Law of cooling. Using your numbers, with To the initial temperature, T(t) = 10 + (To-10)e^(-kt) Now you have T(1) = 10 + (To-10)e^-k = 40 T(2) = 10 + (To-10)e^-2k = 25 (To-10)e^-k = 30 (To-10)e^-2k = 15 (To-10)^2 e^-2k = 900 (To-10) e^-2k = 25 Now ...

*September 23, 2016*

**5th grade math**

14+2=6+2x(3+2)

*September 23, 2016*

**Engineering Math, Newtons Cooling Method**

Your DE yields v = c e^(-2t) + 4.9 v(0) = 0 means c = -4.9, so v(t) = 4.9 - 4.9e^(-2t) (a) plug in t=1.5 (b) v(∞) = 4.9

*September 23, 2016*

**Physics**

v = 30*sin30° - 9.8t it reaches max height when v=0.

*September 23, 2016*

**maths**

Man. some messy algebra! Clearly there are horizontal asymptotes at y = ±b and curve passes through (a,0). The shape seems to preclude any simple equation or parametric equations. Maybe more later.

*September 23, 2016*

**Algebra**

Treat it as you always do fractions. Multiply by the denominator to clear the fraction: -54/x = -6 -54 = -6x Now it's a cinch, right? |x| is the "size" of x, regardless of whether it is positive or negative. It is defined as |x| = x if x >= 0 |x| = -x if x <...

*September 23, 2016*

**Algebra**

shift left: x -> x+4 stretch: y -> 3y shift up: y ->y+5 g(x) = 3(x+4)^2+5

*September 23, 2016*

**GEOMETRY**

The change in coordinates from A(-6, -3) to B(3, 1) is (3-(-6),1-(-3)) = (9,4) 1/3 of the difference is thus (3,4/3) (-6,-3) + (3,4/3) = (-3,-5/3) (-3,-5/3) + (3,4/3) = (0,-1/3) (0,-1/3) + (3,4/3) = (3,1) The first two points divide AB into 3 equal parts.

*September 23, 2016*

**science**

adage: opposites attract

*September 23, 2016*

**Math**

well, 5+7 = ?

*September 23, 2016*

**math**

50 <= c <= 150

*September 23, 2016*

**math**

I'll just use x for ease of typing (note the use of parentheses to make things clear!) 1/(1+sinx) + 1/(1-sinx) =((1-sinx)+(1+sinx))/((1+sinx)(1-sinx)) = 2/(1-sin^2(x)) = 2/cos^2(x) = 2sec^2(x) By far the most useful trig identity is sin^2(x) + cos^2(x) = 1 It pops up in ...

*September 23, 2016*

**Math**

well, if they are not equal, one must be less than the other.

*September 23, 2016*

**Calculus**

if you don't know that the slope of the curve is given by the derivative, I suggest more study, or google will provide many discussions. Assuming that you believe that the derivative of a function gives the slope of the curve at any point, then you just have to remember ...

*September 23, 2016*

**Operating System**

once you get past the sloppy English, you might provide a little more information, doncha think?

*September 23, 2016*

**12**

well, the numbers are 2k 2k+2 2k+4 2k+6 multiply them and you have 2^4(k(k+1)(k+2)(k+3)) Now, two of those numbers must be even, so the product is divisible by 2^6 In addition, the product of 3 consecutive numbers is divisible by 6, so 2^7*3 = 384 divides

*September 23, 2016*

**math**

original fraction: (x-3)/x (x-3+4)/(x+4) = 3/4

*September 23, 2016*

**value**

each hour, 1/2 - 1/3 = 1/6 of the tank is filled. That should help some...

*September 23, 2016*

**Maths, science**

maximum volume is achieved when the box is a cube. The area of the box is c^2, so each face has area c^2/6 That means the side has length c/√6. v = (c/√6)^3 = c^3/(6√6) Hmmm. Better double-check my math.

*September 23, 2016*

**Chemistry**

figure the moles each mole fills 22.4L at stp

*September 23, 2016*

**dosage calculations**

looks ok to me

*September 23, 2016*

**Calculus**

f'(a) = R means f(a) = Ra + C But, if f is odd, C=0 So, f(-a) = -f(a) = -Ra

*September 23, 2016*

**Algebra**

reflected: y = |-x| stretched: y = 1.5|-x| shifted: y = 1.5|-x| - 4 However, since |-x| = |x| the reflection has no effect.

*September 22, 2016*

**Math**

48,136.47 / 7

*September 22, 2016*

**Math**

40 + 32.60*8

*September 22, 2016*

**geometry incomplete**

no information on the relative placements of the points.

*September 22, 2016*

**Msth**

300+300

*September 22, 2016*

**taxation**

no, it isn't.

*September 22, 2016*

**Math**

1in : 8ft = 1in : 96in = 1:96

*September 22, 2016*

**Algebra**

oops. Forgot to multiply the 4

*September 22, 2016*

**Math**

you have (almost) listed them in order of distance from zero, but smallest means farthest to the left. And even then, 2.4 is closer than 2 1/2

*September 22, 2016*

**Algebra**

by the time you get to algebra, you should know about fractions ... -2x+1/3y=4 -2(-3) + 1/3 y = 4 6 + y/3 = 4 y/3 = -2 y = -6

*September 22, 2016*

**Math (Plz Help ASAP)**

-7 -7(10*60)

*September 22, 2016*

**math**

the difference is 25 km/hr so, 25*12 km

*September 22, 2016*

**Math**

sloppy use of the = signs, there.

*September 22, 2016*

**Algebra**

|n-0| < 6

*September 22, 2016*

**Math**

well, y = 6x-12 plug and chug 6(-3)-12 = -30 ...

*September 22, 2016*

**PHYSICS**

if the acceleration is in the same direction as the velocity, the object speeds up. Otherwise, the acceleration opposes the velocity, so it slows down.

*September 22, 2016*

**Math**

since ln8 = 3ln2 is just a number, you have ∫(2x^2 ln8)dx = ∫2x^2*3ln2 dx = 6ln2∫x^2 dx = 2ln2 x^3 = ln4 x^3 + C Maybe you had a typo, I'm guessing... If so, recall how to do integration by parts: ∫x lnx dx u = lnx du = 1/x dx dv = x dx v = 1...

*September 22, 2016*

**Physical Science/ Chemistry**

reading down the column, they become more reactive.

*September 22, 2016*

**Math**

so, what two numbers add to 9 and one is twice the other? Come on - there aren't that many pairs that add to 9.

*September 22, 2016*

**Math**

x = amt at 4% x-2000 = amt at 5% Now just compare the interest: .05(x-2000) = .75*.04x

*September 22, 2016*

**MATH**

#1A is correct, but it is not scientific notation for the value. #2B is also correct, but not S.N. #3 is 0.593 x 10^4 But, to make it S.N., you need to have 5.93 x 10^3 #4 5.2 x 10^8 / 25 = 0.208 x 10^8 That is 2.08x10^7 Looks like you need some serious review on how to move ...

*September 22, 2016*

**Physics**

v(t) = Vo + at = 85 - 13t It stops when v=0.

*September 22, 2016*

**Algebra**

stop guessing and start working 1/r * s = s/r, so p=s/r + d p-d = s/r Now what do you think?

*September 22, 2016*

**maths**

depends on the value of y. But, since 12y-12 = 12(y-1) it is certainly not prime.

*September 22, 2016*

**Math**

2.3(4.5-9.6)+3.1 = 2.3(-5.1)+3.1 = -11.73+3.1 = -8.63 you are correct. If your input on the calculator is as accurate as your typing here, it is no surprise that is sometimes wrong...

*September 22, 2016*