Physics, Chemistry, Mathematics Forums

Consider an ellipse x²/(a-ib) + y²/(c-id)=1.

Manipulating we get x²/a-ib) - y²/(id-c)=1 which is a hyperbola.Both are imaginary.

Consider an ellipse x²/a²+y²/b²=1.Manipulating,x²/a² - y²/-b²=1

Which is x²/a²-y²/(ib)²=1.The first one is a real ellipse and the second one is an imaginary hyperbola.But in the 1st case both are imaginary and it represents 2 curves.Can someone explain that?

int 1/tanx+cotx+secx+cosecx

sir,

   please help me out with this problem

      integral of (1+x²)\(1+x⁴) w.r.t dx

Can anyone show me how the graphs of xe^-x and  xe^-x^2 look like? Why?

how to determine the limits while integrating in electrostatics for example while finding intensity at a point by a long verticle conductor we take limits as -theta to theta but will we find the intensity along the axis of a circular ring we take limits as 0 to Q

please explain this

hi friends,

In electro magnetic waves electric fields are perpendicular to magnetic fields .So when these fall on a charge is there any acceleration on the charge?

A thin uniform heavy rod of length L hangs from a horizontal axis through one end.what is the minimum angular velocity that must be imparted to rotate it through a right angle

You have five pieces of strings. You pick two ends out of the 10 at random and tie a knot. (You may tie both ends of a string together).  Then you pick two ends again out of the remaining 8 and tie them. You keep doing this until there are no ends left. What is the expected value of the number of loops you will end up with? What is the expected value if there are six strings?