Home
PYQ PracticeFree
JEE Rank Predictor
Answer Key

Mathematics - Vector Question with Solution | TestHub

MathematicsVectorDot Product & Its Application ( Projection etc.)Medium2 minPYQ_2020

MathematicsMediumnumerical

If $\vec{x}$ and $\vec{y}$ be two non-zero vectors such that $|\vec{x} + \vec{y}| = |\vec{x}|$ and $2 \vec{x} + λ \vec{y}$ is perpendicular to $\vec{y}$ , then the value of $λ$ is ...... .

Answer:

1.00

Solution:

${|\vec{x} + \vec{y}|}^{2} = {|\vec{x}|}^{2}$

$\Rightarrow {|\vec{y}|}^{2} + 2 \vec{x} . \vec{y} = 0$ .....(1)

and $(2 \vec{x} + λ \vec{y}) . \vec{y} = 0 s$

$\Rightarrow λ {|\vec{y}|}^{2} + 2 \vec{x} . \vec{y} = 0$ .....(2)

by (1) and (2) $λ = 1$

Stream:JEESubject:MathematicsTopic:VectorSubtopic:Dot Product & Its Application ( Projection etc.)

⏱ 2mℹ️ Source: PYQ_2020

Doubts & Discussion

Loading discussions...