Need help comics question (1 Viewer)

[Ambility]

The condition for y=mx+c to be tangent to the ellipse x^2/a^2+y^2/b2=1 is c^2=a^2m^2+1. Prove the pair of tangents to x^2/25+y^2/16=1 which pass through the point (4,5) are perpendicular.

 

[DatAtarLyfe]

The condition is c^2=a^2m^2 + b^2

 

[Ambility]

The condition is c^2=a^2m^2 + b^2

Cheers mate that makes perfect sense, except your middle term of the expansion of (y-mx)^2 is wrong, but it doesn't affect the product of roots.

 

[DatAtarLyfe]

Cheers mate that makes perfect sense, except your middle term of the expansion of (y-mx)^2 is wrong, but it doesn't affect the product of roots.

whoops yep its meant to be 2mxy XD