Rotating the Line y=-1 in Bounded Region R (y=9-x^2, y=0, x=0)

[xstetsonx]

Consider the region R bounded by y=9-x^2, y=0, x=0. rotate the line y=-1

I am not sure about the bounds. The outer radius is -1 , and the inner radius is -10+x^2 right? but after i do the calculation i got a negative value. does that mean i got the radius wrong?

 

[tiny-tim]

Hi xstetsonx!

(try using the X² tag just above the Reply box )

Consider the region R bounded by y=9-x^2, y=0, x=0. rotate the line y=-1

I am not sure about the bounds. The outer radius is -1 , and the inner radius is -10+x^2 right? but after i do the calculation i got a negative value. does that mean i got the radius wrong?

How can a radius be negative?

The inner radius is 1 , and the outer radius is 10 - x².

 

[xstetsonx]

hahahaha omg i am an idiot hahahaha