Current Events > I think I just got the easiest quiz I ever got (Calc 3)

(+) Yeah! (+)

The question was what was the equation of a sphere with a Center (x, y, 6) that touches the xy plane. I don't remember what x and y were, but that's not the point. Just say x and y were 3 and -2. Well, you already know that the equation will be (x-3)^2 + (y+2)^2 + (z-6)^2 = r^2, but since you know that z = 0 when the sphere touches the xy plane, then you already know that the radius is however far the center is from the xy plane (aka, 6).

To make matters worse, my instructor gave us the answer since she said basically all that just in case it didn't connect with you that the sphere would not be intersecting with the xy plane but just scraping it meaning z=0.

I studied for a good chunk about converting equations into the standard equation of a sphere and all these vector things for nothing, lol.


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And in case it sounds like I'm complaining, I'm not, I just thought it was funny. I still half-way feel that it was "too easy" but nah.

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Calm down Einstein.

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