## anonymous one year ago Calculus III: Find an equation of the largest sphere with center (7, 6, 9) that is contained in the first octant. I assumed the radius would be 6 since it was the smallest of the three, and that the problem would be (x-7)^2 + (x-6)^2 + (x-9)^2 = 36, but that turned out to be wrong. Where is the "first octant"? Would that be the XY-plane?

1. anonymous

the first octant is the positive xy region |dw:1442372494384:dw|

2. misty1212

seems right to me, except you have way to many x's there

3. anonymous

Oh, I put three x's instead of x, y, and z. Never mind! Sorry, guys!

4. misty1212

lol!!

5. anonymous

youre right in saying that the 6 is the limiting factor here. I think you have the right idea, just try tweaking your equation slightly like this: $\left( x-7 \right)^2+\left( y-6 \right)^2+\left( z-9 \right)^2-36=0$

6. anonymous