- #1
crowdedscience
- 6
- 0
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 into the equation (y-y1)=m(x-x1), but that didnt work out
any ideas?
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 into the equation (y-y1)=m(x-x1), but that didnt work out
any ideas?