Recent content by rizardon

While working on an integration problem I found that I will arrive at two different solutions depending on how I approach it. I'm finding the arc length of y=ln(1-x2) on the interval [0,0.5] The formula for finding the arc length is ∫sqrt[1+[f'(x)]2]dx So f'(x) = -2x / ( 1-x2 ) Here...

Thanks, I get it now.

Thanks a lot. I get the first part now. But I still don't get the second part. We only know the two triangles share the same height so how can we deduce that their areas are in the same proportion without knowing the relationship between the heights. Sorry, but I really suck in geometry.

Homework Statement Let A, B, C be three points on a plane and O be the origin point on this plane. Put a = OA and b = OB, and c = OC, (a,b and c are vectors). P is a point inside the triangle ABC. Suppose that the ratio of the areas of the triangles PAB, PBC and PCA is 2:3:5 (i) The...

Homework Statement int[1/1+3cos^2(x)]dx Homework Equations The Attempt at a Solution It shouldn't require any techniques of integration other than u-substitution. I tried letting u = sqrt(3)cos(x) and u = tan(x/2) but both didn't work so I think I need to multiply some...

The identities are all for Jp(x). Can I just replace x with bx or do i need to apply other properties to do so. Thanks.

Homework Statement Show that the integral (from 0 to infinity) of e-axJp(bx)dx = [sqr(a2+b2) - a] / bpsqr(a2+b2) Homework Equations Jp(bx) = summation [ (-1)k(bx/2)2k+p ] / k! Gamma(k+p+1) Gamma(x) = integral (from 0 to infinity) of e-ttx-1dt The Attempt at a Solution...

Why don't you try and do the partial fraction. I think it should work.

Homework Statement 2.5-13. Let x equal the number of flips of a fair coin that are required to observe heads-tails on consecutive flips (a) Find the p.m.f. of x (b) Determine the values of the mean, variance and standard deviation. 2.5-17. From 1999-2002 Red Rose Tea randomly placed one...

Can I combine the 20(ohm) with the 10(ohm) resistor?

Homework Statement In the circuit shown in the figure below the current through the 12.0V battery is measured to be 70.6 mA in the direction shown. What is the terminal voltage Vab Homework Equations V=E-IR I1=I2+I3 The Attempt at a Solution First I set Vab= E-IR= 24 - 10(I1)...

The potential difference is V=k(integral)dq/r V=-(integral)Eds=-(integral)Edr=-(integral)kQ/r2dr=-kQ(integral from a to b)dr/r2=kQ(1/b - 1/a) Is this right

Yes, I have, but using the law is quite confusing. How will finding the potential difference make any difference, since my Va would be 0 and what's left is Vb which is kq/r?

Homework Statement Consider two thin conducting spherical shells. The inner shell has a radius r1=15cm and a charge of 10.0 nC. The outer shell has a radius r2=30cm and a charge of -15.0 nC. Find a)the electric field E and b)the electric potential V in A, B and C, with V=0 t r=infinity...

Homework Statement The auditory canal of the human ear extends about 2.5 cm from the outside ear to the eardrum (a)Explain why the human ear is especially sensitive to sounds at frequencies around 3500Hz. Homework Equations Speed of sound v=344m/s The Attempt at a Solution I know...