Hi Mike,

Can you please do practise test 7, section 4, question 29 (Whats the fastest way to do it which doesn’t involve using the distance formula for every answer option)

Yeah, NO distance formula! The way to get this one is to know the standard formula for a circle and to recognize that it’s basically given to you here. The standard formula for a circle of radius r centered at (hk) is (x-h)^2+(y-k)^2=r^2.

Therefore, (x+3)^2+(y-1)^2=5^2 means you have a circle of radius 5 centered at (–3, 1). Once you know the center, you shouldn’t have to do the distance formula to recognize that (3, 2) is more than 5 units away from (–3, 1).

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