Aspire's Library
A Place for Latest Exam wise Questions, Videos, Previous Year Papers,
Study Stuff for MCA Examinations - NIMCET
Study Stuff for MCA Examinations - NIMCET
Previous Year Question (PYQs)
If the image of the point $P(a, 2, a)$ in the line
$\dfrac{x}{2} = \dfrac{y + a}{1} = \dfrac{z}{1}$
is $Q$ and the image of $Q$ in the line
$\dfrac{x - 2b}{2} = \dfrac{y - a}{1} = \dfrac{z + 2b}{-5}$
is $P$, then $a + b$ is equal to ______.
Solution
Direction vector of first line: $(2,1,1)$
Using reflection property
$\dfrac{2\lambda - a + a}{2} = -5\mu - 2b$
and
$\dfrac{a + 4\lambda - a}{2} = 2\mu + 2b$
Solving
$\lambda - \mu = b$
$\lambda - \mu = 2a$
$\Rightarrow b = 2a$
Further solving
$a = 1 \Rightarrow b = 2$
$\Rightarrow a + b = 3$
Online Test Series, Information About Examination,
Syllabus, Notification
and More.
View More
Online Test Series, Information About Examination,
Syllabus, Notification
and More.
View More
Ask Your Question or Put Your Review.
