Question below:

Question

Question below:

aravindg · Answer

attachment

kc_kennylau · Answer

f is a constant right

aravindg · Answer

Yep.

kc_kennylau · Answer

Is calculus allowed?

aravindg · Answer

Yes any method is allowed. The question is from a previous year objective test. So they only want the answer and do not check the method.

kc_kennylau · Answer

$$x^2+y^2+2fy+\lambda=0$$$$x^2+y^2+2fy+f^2=f^2-\lambda$$$$x^2+(y+f)^2=f^2-\lambda$$
$$x^2+y^2+2fy+\mu=0$$$$x^2+y^2+2fy+f^2=f^2-\mu$$$$x^2+(y+f)^2=f^2-\mu$$

kc_kennylau · Answer

So the two circles have the same center

kc_kennylau · Answer

What does "tangent" mean in that context?

aravindg · Answer

Well I am a bit confused on that one. Obviously its easy to get a tangent for inside circle.

zepdrix · Answer

|dw:1397895940780:dw|Tangent to the inner circle.. is what I think they mean

zepdrix · Answer

But it wouldn't have to be horizontal like that I guess +_+
Hmm

aravindg · Answer

Well it says "any point" :)

zepdrix · Answer

|dw:1397896087451:dw|As long as the line is tangent to the surface from that point then I think they all end up the same length yes? :3
Neat problem!

anonymous · Answer

The bigger circle |dw:1397896186227:dw|
tangent from any point on the bigger circle to the smaller one.
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