Let `xa n dy`
be real variables satisfying `x^2+y^2+8x-10 y-40=0`
. Let `a=max{sqrt((x+2)^2+(y-3)^2)}`
and `b=min{sqrt((x+2)^2+(y-3)^2)}`
. Then
`a+b=18`
(b) `a+b=sqrt(2)`
`a-b=4sqrt(2)`
(d) `adotb=73`
A. a+b=18
B. `a-b=4sqrt2`
C. `a+b=4sqrt2`
D. a.b=73
