17.12.09

#395 1800-HELP

Year 12's got their HSC marks back today and yesterday. Hope everyone did really good! :D

I can't figure out how to do this question (on Perpendicular distance to a line) .. like it's probably really easy, though. :0

7. Show that the line
a. √3x + y = 5 cuts the circle x² + y² = 9 in two places.
b. 12x - 5y = 32 lies entirely outside the circle x² + y² = 4.
c. 4x + 3y + 18 = 0 is a tangent to the circle centre (-1, 2) with radius 4 units.

Oh wait ..
7a. Do I just sub in the centre of the circle (0, 0) into the perpendicular distance formula .. and make that be less than 3 (cuz the radius is 3)? And .. Yeah Idk what to do after that. :(

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