Aspire's Library

A Place for Latest Exam wise Questions, Videos, Previous Year Papers,
Study Stuff for MCA Examinations - NIMCET

Previous Year Question (PYQs)

If $z$ is any complex number with $|z-3-2i|\le2$, then the minimum of $|\,2z-6+5i\,|$ is:




Solution

Put $w=z-(3+2i)$ so $|w|\le2$. Then $2z-6+5i=2w+9i$. Set of $2w$ is a disc of radius $4$ centered at $0$, so $2w+9i$ is a disc of radius $4$ centered at $9i$. Minimum modulus $=\big||9|-4\big|=5$.

Online Test Series,
Information About Examination,
Syllabus, Notification
and More.

Click Here to
View More

Online Test Series,
Information About Examination,
Syllabus, Notification
and More.

Click Here to
View More
Ask Your Question or Put Your Review.

loading...