I invite you to post your favorite solutions to this problem we discussed in math class today:
Find the equations of the tangents to the circle x2 + y2 - 4x + 2y - 20 = 0 through (9,-2).
Find the equations of the tangents to the circle x2 + y2 - 4x + 2y - 20 = 0 through (9,-2).
1 comment:
i did it, may be wrong, i got two solutions, as expected. i used the formula that d=|(Ax1+By1+C)/√(A^2+B^2)| -- i hope it's clear. with this, i got ~3.07 and ~-1.16 for the slope. out of this, the tangents' equations should be y=3.07x-29.62 and y=-1.16x-12.47
are those correct?
- Balint Erdos
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