Recent content by crowdedscience

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    Solving Tangent to Ellipse: x^2+5y^2=5, y=mx+c

    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?
  2. C

    Solving Tangent to Ellipse: x^2+5y^2=5, y=mx+c

    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
  3. C

    Solving Tangent to Ellipse: x^2+5y^2=5, y=mx+c

    the derivative of x^2+5y^2=5 was dy/dx=-x/5y
  4. C

    Solving Tangent to Ellipse: x^2+5y^2=5, y=mx+c

    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...
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    Charge on two suspended metal balls

    oh wow, oopsies!
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    Charge on two suspended metal balls

    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...