Let A={z∈ℂ:|z-2|≤4} and
B={z∈ℂ: |z-2|+|z+2|=5}.
Then the max {|z1-z2|:z1∈A and z2∈B} is: [2026]
(4)
|z-2|≤4⇒(x-2)2+y2≤16
|z-2|+|z+2|=5⇒x2a2+y2b2=1
⇒4x225+4y29=1
Maximum value of |z1-z2|=6+52=172