Recent content by absci2010

Yes, but that's the part I'm confused about. Where does the value (1/2)(1-cos1) come from?

Homework Statement Show that 1/2(1-cos1)\leq\int\intsinx/(1+(xy)4)dxdy\leq1 on the area 0\leqx\leq1, 0\leqy\leq1. Homework Equations Mean Value Inequality: m*A(D)\leq\int\intf(x,y)dA\leqM*A(D), where m is the minimum and M is the maximum on the interval. The Attempt at a Solution...

The .59g is the weight of the unknown. We DON'T know the weight of the unknown before we put it in the tube, so we have to measure it. We use the ideal gas law equation (PV=nRT) to find the number of moles. However, we can't use the ideal gas law for a liquid (obviously). So we heat it up so...

No, a dumas tube has a very narrow neck, so we are assuming that none of the substance was lost.

Sure. We weighed the empty dumas tube to determine the mass of the tube plus the air in it. Then, a small amount of an unknown volatile substance was put in the tube. We heated the tube in a beaker of boiling water until all of the substance became gas. Then we let it cool to room temperature to...

Homework Statement We were given a volatile substance and a Dumas tube and told to find the moles of the unknown as well as its molar mass. We also had to measure the volume of the tube, air pressure, and the temperature at which all of the substance was a gas. Pressure=750mmHg=0.987atm...

Thanks so much! I realized after I posted the question that it's not discontinuous. Oops. >.<

f(x,y)= xy2/(x2+y2) if (x,y)\neq(0,0) =0 if (x,y)=(0,0) Show that the partial derivatives of x and y exist at (0,0). This may be a really stupid question, but would the partial derivatives of x and y at (0,0) just be 0? I tried taking that partial derivatives of xy2/(x2+y2) and...

Sorry, it should be: x=rcos\thetasin\varphi y=rsin\thetasin\varphi z=rcos\varphi

1. Find the derivatives of the spherical coordinates in terms of df/dx, df/dy, and df/dz. 2. f(x,y,z) x=rcos\thetasin\varphi y=rsin\varthetacos\varphi z=rcos\varphi 3. The Attempt at a Solution [/b] I took the derivatives of the three equations and I got...