Question

If the complex number $z$ lies on the boundary of the circle of radius 5 and centre at 4 , then the greatest value of $|z+1|$

• A. 4
• B. 5
• C. 10
• D. 9

Answer 1

Answer: (C)

As -1 lies on the circle $|z-4|=5$, the real number $|z+1|$ is maximum when $z$ is the other end point of the diameter.