Recent content by doctordiddy

Homework Statement You purchase a chainsaw, and can buy one of two types of batteries to power it, namely Duxcell and Infinitycell. Batteries of each type have lifetimes before recharge that can be assumed independent and Normally distributed. The mean and standard deviation of the lifetimes...

I am unsure of how to continue after For ##X \sim U(0,1)##, what does this give you for ##F(y)##? Am I supposed to see that X = ln(y) or am I supposed to see that Y ~ U(1,e)? Or am I missing something altogether?

I found the answer to be e^0.5, but I am not sure exactly why. Do we find the median of the uniform distribution of X (0.5) and then plug that into e^(X)? Or do I need to find the median of the distribution between 1 and e? If it's the latter, how do we know that the median is simply e^(0.5)...

I found the answer to be e^0.5, but I am not sure exactly why. Do we find the median of the uniform distribution of X (0.5) and then plug that into e^(X)? Or do I need to find the median of the distribution between 1 and e? If it's the latter, how do we know that the median is simply e^(0.5)...

Homework Statement Suppose X has the Uniform (0,1) distribution. Find the median of the distribution of e^X correct to 2 decimals. Homework Equations F(X) = 0.5 F(X) = ∫f(x) The Attempt at a Solution I am not entirely sure what to do here, I know to find the median you need to find when F(X)...

oh right thanks, i used ∫secx=ln(secx+tanx) and it worked. Just a question about the hyperbolic sine, would you mind explaining it a bit to me or linking me to a good place that explains it? I don't think I've been taught it yet but one of the listed possible solutions has arccosh in it, and I...

oh you're right, but after solving the integral i still end up with tanθsecθ.. Unless i am doing something wrong in finding my θ values for x=3 and x=0?

Homework Statement evaluate the definite integral ∫(0 to 3) dx/sqrt(25+x^2) Homework Equations The Attempt at a Solution I first used substitution and set x=5tanθ, and dx=5tanθsecθdθ then i wrote the integral as 5∫ tanθsecθdθ/sqrt(25(1+tan^2(θ)) after some simplification i...

oh i see. I forgot to change that when i was trying to do it another way previously. Thanks for the help!

Homework Statement http://imgur.com/BWo3tLh Using the fact that the weight of water is 62.5lb/ft3, find the work (in ft-lbs) required to pump the water out of the outlet when r =3ft. Make sure your answer is correct to within ten ft-lbs. Homework Equations The Attempt at a...

Homework Statement http://imgur.com/P9udvTs Homework Equations The Attempt at a Solution So I set the scalar multiples of a, b, and c as x,y,z so i had 3 equations 4x-4y+4z=0 -4x+4y-4z=0 -2x-4y-5z=0 i tried solving it numerous times each time trying to use a different...

how would you tell which two are going in the same direction and which one is going in the opposite direction?

So according to kirchhoffs junction rule, all currents entering a node must be equal to currents exiting a node. In this example http://imgur.com/4Zqb21A If we take a node as the point between the 4 ohm resistor, 5 ohm reisistor, and the 20V battery, how would you be able to determine an...

Homework Statement Find the volume of a pyramid with height 24 and with base an equilateral triangle with side 11. Homework EquationsThe Attempt at a Solution So I know the relationship h/x=b/l where h is my height 24 x is simply x or height above base b is my base 11 l is the length of the...

Homework Statement Find the area of the region enclosed between y=4sin(x) and y=3cos(x) from x=0 to x=0.3π. Homework Equations The Attempt at a Solution So I know how to do most of this question, the area i am stuck on is finding the intersection point between the two...