# Search results

1. ### Density Function and E(x)

Density Function and E(x)[solved] The density function of X is given by https://webwork.math.lsu.edu/webwork2_files/tmp/equations/48/83b2bf602cc895a007a673a9a23c3c1.png If the expectation of X is E(X)=-1, find a and b. The Attempt at a Solution I'm actually working ahead of the...
2. ### Probability of current flow through circuit

The probability of the closing of the ith relay in the circuits shown is given by p_i. Let p_1 = 0.9, p_2 = 0.6, p_3 = 0.1, p_4 = 0.7, p_5 = 0.2. If all relays function independently. what is the probability that a current flows between A and B for the respective circuits...
3. ### Expected Value (probability problem)

Prizes and the chances of winning in a sweepstakes are given in the table below. Prize: Chances $25,000,000: 1 chance in 400,000,000$250,000: 1 chance in 150,000,000 $75,000: 1 chance in 50,000,000$10,000: 1 chance in 4,000,000 \$800,000: 1 chance in...
4. ### Mean and standard deviation problem

The mean and standard deviation of a random variable x are -11 and 4 respectively. Find the mean and standard deviation of the given random variables: 1) y=x+7 2) v=8x 3) w=8x+7 2. Homework Equations : E(x) = u, E(ax+b) = aE(x)+b The Attempt at a Solution I've gotten...
5. ### Defining probability events

A box contains one yellow, two red, and three green balls. Two balls are randomly chosen without replacement. Define the following events: A: \{ One of the balls is yellow \} B: \{ At least one ball is red \} C: \{ Both balls are green \} D: \{ Both balls are of the same color \} The...
6. ### Probability defective computer problem

A computer retail store has 14 personal computers in stock. A buyer wants to purchase 3 of them. Unknown to either the retail store or the buyer, 3 of the computers in stock have defective hard drives. Assume that the computers are selected at random. What is the probability that exactly one...
7. ### Elementry Probability problem

An elementary school is offering 3 language classes: one in Spanish, one in French, and one in German. These classes are open to any of the 98 students in the school. There are 38 in the Spanish class, 30 in the French class, and 18 in the German class. There are 13 students that in both Spanish...
8. ### Outputting to the parallel port (assembly 8086)

So I'm having a problem in some code I'm working on in Assembly(8086). I've tried everything I can think of, but I can't seem to figure out the problem. So I have a circuit that I built with a DB25 plug so that it can communicate with the parallel port on the computer. All we had to do is...
9. ### Pspice and Ring Oscillator

Design a digital ring oscillator using logic inverters that have propagation delay times of tPLH = 28ns and tPHL = 42ns. The Attempt at a Solution I'm using a general ring oscillator design using 3 CMOS inverters like this...
10. ### TTL wave and Pot in Pspice

Can someone explain to me how to create a 0-3V TTL waveform at 20 Hz in Capture (Pspice)? - edit: Figured out how to adjust the pot, but still can't figure out the TTL waveform.
11. ### TTL waveform

A 20Hz TTL waveform is applied to the circuit... The Attempt at a Solution - I'm working an activity for my lab tomorrow (not actually due for any points, just to help us get an understanding of the lab), but I'm not really sure what it means when it says a "20 Hz TTL waveform"...
12. ### 9's complement

Find the 4-digit complement of a) 0232 b) 9644 The Attempt at a Solution I'm not really sure what is being asked here. When asked what form the numbers were given in and whether the problem was talking about 9's complement, his response was "the answer is 9's complement". So I don't...
13. ### Reactive power compensation

Calculate the capacitance C needed for the load compensation to unity power factor. Calculate the rms value E of the needed distribution voltage e before and after compensation. Calculate the active power loss (delta)Ps at energy delivery before and after compensation. U = 2.4kV (line to...
14. ### Engineering Modifying rectifier circuit to include LED indicator

You bought a charger that does not have a charging satus indicator. Assuming that a regular rectifier circuit configuration (such as this: http://www.physics.udel.edu/~nowak/phys645/AC_circuits_files/image016.jpg ) is used for the charger, modify the rectifier circuit to have LED indicator(s)...
15. ### Hand cranked radio question

hand cranked radio question (ignore - figured out) Your two friends argued whether they should crank more cycles (e.g. 180 cycles in 1 minute) or longer time (e.g. 180 cycles in 2 minutes) to efficiently charge the internal batteries. They couldn't conclude with their knowledge and decided to...
16. ### Unsure how to work algebra problem

(s^2+4s+4)/(s^2+4s+5) = 1 - (1/(s^2+4s+5) The Attempt at a Solution I'm actually pretty far up into my upper level math classes (past calc 3), but I can't seem to figure out this one. How do you go from the left side to the right side of the equation?
17. ### Karnaugh map for state table.

Derive the circuit that implements the state table http://silvercurvemedia.com/alex/flyers/state%20table.jpg The Attempt at a Solution I know you can get your equations for the circuit from either the table itself or through a Karnaugh map, but I prefer using a karnaugh map. How exactly...
18. ### Drawing D flip flop using T flip flop

Draw a D flip-flop using a T flip flop and combinational logic The Attempt at a Solution - I'm not even sure where to start with something like this. I'm trying to figure out how they relate and how you would be able to use one to draw the other. I know that in the standard design...
19. ### SR Latch problem

-NOTE: I figured the problem out. Please ignore. Draw a similar latch using NAND gates (from one using NOR gates). Derive its characteristic table and show its timing diagram, given the R and S inputs. S R Qa Qb ------------ 0 0 0/1 1/0 (no change) 0 1 0 1 1 0 1 0 1 1...
20. ### Global extreme values

find global min/max: f(x,y)= x^3-2y ; 0<=x, y<=1 The Attempt at a Solution - I know that the critical points don't work since there are none, but what I'm not understanding is how to draw the square from 0<=x, y<=1. The solutions has the points (0,0), (1,0), (1,1), (0,1), but I'm...
21. ### Using Jacobian to determine area

Let [phi](u,v)=(3u+v,u-2v). Use the Jacobian to determine the area of [phi]R for: R=[2,5]X[1,7] The Attempt at a Solution - I'm really not sure why I keep getting the wrong answer on this problem. the problem gives you two R's to solve for and I got the right answer for the first...
22. ### Finding image under phi

Let [phi](u,v)=(u^2,v). Is phi one-to-one? If not, determine a domain on which phi is one-to-one. Find the image under phi of: - The rectangle R=[-1,1]X[-1,1] The Attempt at a Solution - I'm not sure at all how to determine whether phi is one-to-one or not, so if somebody can...
23. ### System of equations

[lambda]=3/(2x) = 1/(2y) = 1/(3z) with constraint eq. x^2+2y^2+6z^2=1 The Attempt at a Solution - I can't figure out how to solve this system of equations. Can somebody please help.
24. ### Lagrange Multipliers

find min/max: f(x,y)=xy with constraint being 4x^2+9y^2=32 [gradient]f=[lambda]gradient g The Attempt at a Solution I thought I understood the Lagrange problems, but I can't seem to get the minimum right on the last few problems. I get x=+/-2 and then plug back in to find y, then I use...
25. ### Global extreme values

determine the global extreme values of the function on the given domain: f(x,y)=x^2+2y^2 , 0<=x,y<=1 The Attempt at a Solution - I know you need to evaluate the critical points first and then use the boundary to find the maximum and minimum values, but I can't seem to get the...
26. ### Multi variable derivative

whats derivative of arctan (xy) with respect to x The Attempt at a Solution - I feel kind of stupid for this one, but I can't seem to figure out the derivative here. I know with one variable that arctan goes to 1/(1+x^2), but I'm not sure what to do with two variables. please help.
27. ### Chain Rule problem

use chain rule to evaluate partial derivative of g with respect to theta at (r,[theta])=(2*sqrt(2),pi/4), where g(x,y) = 1/(x+y^2), x=rsin[theta] and y=rcos[theta] [b] r^2=x^2+y^2 and tan[theta]=y/x [b] The Attempt at a Solution I understand how to use the chain rule for partial...
28. ### Multi variable limits

Evaluate the limit or determine that it DNE lim as (x,y) goes to (0,0) of [(sinx)(siny)]/(xy) The Attempt at a Solution I can solve these when the denominator isn't zero, but pretty much rest of my homework deals with that situation. I'm really not sure how you solve...
29. ### Multiplicity in eigenvalues

Can someone please explain multiplicity to me? I've been able to solve the problems involving it, but I'm not quite sure what it means in terms of the eigenvalue. Thanks.
30. ### Engineering Circuit analysis question

solve Vo in as many ways as possible The Attempt at a Solution - This is more of a question to find out if there are any other possible ways of solving this problem. So far I have solved using: Nodes, Mesh, Loops, Superposition, Thevenin and Superposition Combined, Norton...