sorry, I'm starting to feel stupid now, but I just don't see how (q(1+5m^2))^2=5m^2+1. Also I'm not familiar with fermat's approach, what does that involve?
ok, so I did
y-y1=m(x-x1)
y-q=-p/5q(x-p)
y=-px/5q + p^2/5q + q
y=(-p/5q)x + (p^2/5q + q)
so then c=p^2/5q + q
but then when I put that into c^2=5m^2+1, it isn't equal
what did I do wrong?
Thanks
An ellipse has the equation x^2+5y^2=5
a line has the equation y=mx+c
a) show that if the line is a tangent to the ellipse then c^2=5m^2+1
b) hence find the equation of the tangent parallel to the line x-2y+1=0
I tried to find the gradient of x^2+5y^2=5 at a point (x1,y1) and then put it...
Homework Statement
Two very small metal coated foam spheres, each of mass 2.80x10^-6kg, are attached to nylon threads 45cm long and hung from a common point. When the spheres are given equal quantities of negative charge, each supporting thread makes an angle of 15 degrees with the vertical...