Question 377 of 455MediumMCQ
The locus of the centre of a circle which touches the circle ∣z−z1∣=a and ∣z−z2∣=b externally (z,z1,z2 complex) will be Solutions · 1
Official solution
If the centre is z0 with radius r: ∣z0−z1∣=r+a, ∣z0−z2∣=r+b, so ∣z0−z1∣−∣z0−z2∣=a−b (constant), the defining property of a hyperbola. Answer the question to unlock