Post Your Maths Problems Here

[SteveGrabowski]

Anyone who really likes math should check these videos (full course on the playlist these are on) from an awesome abstract algebra course at Harvard. It uses maybe the best written textbook at the undergrad level: namely, Algebra by Michael Artin.

 

 

 

 

For anyone bored with calculus, check this great real analysis course from Harvey Mudd College (one of the best undergrad degrees in the US to get for engineering, math, physics). The textbook it uses isn't so great, Principles of Mathematical Analysis by Walter Rudin, but the book has some really awesome and difficult homework problems. This is also another full course if you go to the playlist this video is on.

 

[A.D.A.M]

Yep that's right.

Also part c can be done without even doing b since they gave you the expression. It's a handy little thing; whenever you get a 'show that' question just remember that you can use that equation for the remainder of the question even if you were unable to derive it (just some exam advise )

I cant seem to find the are of the square that would give me what b is.Do you rearrange the formula to get 'x' and square it?

[Kingofpants]

.... umm.... Oh, BATMAN!

It actually makes a batman.

[Mujteba]

I cant seem to find the are of the square that would give me what b is.Do you rearrange the formula to get 'x' and square it?

Area of the square is x^2 because the side length is x. Take that and add to Acircle then collect like terms; from there you will get the answer in the required form. You are certainly on the right track, now just don't allow your algebra to let you down  .

[AlexStriz]

Yay for daily AP Chem. quizzes! This is the quiz from yesterday. Not from a math class, but it did involve some math

 

1 - A gas absorbs 0.0 J of heat and then performs 15.2 J of work.  The change in internal energy of the gas is...

2 - Calculate the work for the expansion of CO2 from 1.0 to 2.5 liters against a pressure of 1.0 atm at constant temperature.

3 - Of energy, work, enthalpy, and heat, how many are state functions?

4 - Which of the following statements correctly describes the signs of q and w for the following exothermic process at     P = 1 atm and T = 370 K?

H2O(g) → H2O(l)

5 - One mole of an ideal gas is expanded from a volume of 1.00 liter to a volume of 10.00 liters against a constant external pressure of 1.00 atm.  How much work (in joules) is performed on the surroundings?  (T = 300 k; 1 L atm = 101.3 J)

6 - Consider a gas in a 1.0 L bulb at STP which is connected via a valve to another bulb which is initially evacuated.  Answer the following concerning what occurs when the valve between the two bulbs is opened. What is true about the value of ΔH?

7 - Two metals of equal mass with different heat capacities are subjected to the same amount of heat.  Which undergoes the smallest change in temperature?

8 - A 25.0 g piece of aluminum (which has a molar heat capacity of 24.03J/°Cmol) is heated to 82.4°C and dropped into a calorimeter containing water (specific heat capacity of water is 4.18J/g°C) initially at 22.3°C.  The final temperature of the water is 24.9°C.  Calculate the mass of water in the calorimeter.

9 - Consider a rigid insulated box containing 20.0 g of He(g) at 25.0°C and 1.00 atm in one compartment and 20.0 g of N2(g) at 115.0 °C and 2.00 atm in the other compartment.  These compartments are connected by a partition which transmits heat.  What will be the final temperature in the box at thermal equilibrium?  (Cv(He)= 12.5 J/K mol, Cv(N2)= 20.7 J/K mol)

10 - Using the following data, calculate the standard heat of formation of the compound ICl in kJ/mol:

ΔH° (kJ/mol)

Cl2(g) → 2Cl(g) 242.3

I2 (g) → 2I(g) 151.0

ICl(g) → I(g) + Cl(g) 211.3

I2(s) → I2(g) 62.8

 

There was a serious fluctuation between very easy and hard questions

[Guest]

1. cos^2x-3/2cos2x=0

2. cos2x+4cosx=-3

3. sin2xcscx=1

 

use identities to reduce power. I need steps and thanks