Aspire's Library

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

Previous Year Question (PYQs)



Let $ z $ be a complex number such that $ |z - 6| = 5 $ and $ |z + 2 - 6i| = 5 $. Then the value of $ z^3 + 3z^2 - 15z + 141 $ is equal to





Solution

Center of first circle $ C_1(6,0),; r_1 = 5 $


Center of second circle $ C_2(-2,6),; r_2 = 5 $


$ \therefore C_1C_2 = r_1 + r_2 $


$ \therefore $ common point $ Z $ is mid point of $ C_1 $ & $ C_2 $


[Image used in solution — two circles diagram]


$ z = 2 + 3i $


$ z^2 = 4z - 13 $


$ z^3 = 3z - 52 $


$ z^3 + 3z^2 - 15z + 141 = 50 $



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...