Differential Calculus

Differential Equations
Find the differential equations of the following family of curves.

1. Parabolas with axis parallel to the y – axis with distance vertex to focus fixed as a.
2. Parabolas with axis parallel to the x – axis with distance vertex to focus fixed as a.
3. All ellipses with center at the origin and axes on the coordinate axes.
4. Family of cardioids.
5. Family of 3 – leaf roses.

Great website, I really like it very much.
Is there any tutorial for getting the inverse of matrix (let say matrix 6x6)?

Thanks and Regards

I need help

After deriving an equation I have ended up with equation where I have a complex denominator and I am not sure how to simplify. I am trying to work out as a function of x. Equation link is below. Thanks in advance.

https://www.flickr.com/photos/baldypaul/32722700004/in/datetaken/

∈=p/Ao((1-(x/2L) *E^(-1)

I am trying to integrate the above. For clarity p is over Ao((1-(x/2L) and then all multiplied by E^(-1). Do I need to deal with the Ao((1-(x/2L) first?

Thanks in advance Paul

At 2:00PM, a thermometer reading 80°F is taken outside where the air is 20°F. At 2:03PM, the temperature reading yielded by thermometer is 42°F, later the thermometer was brought inside where the air is at 80°F, at 2:10PM the reading is 71°F. When was the thermometer brought indoor?

Hello ,please someone should help with out with these Diffrential equations
a. xdy + ydx = x^3 y^6 dx
b. cosysin2xdx +(cos^2y - cos^x)dy = 0