Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Determinants

Question:

A ball is thrown upwards from the plane surface of the ground. Suppose the plane surface from which the ball is thrown also consists of the points A(1, 0, 2), B(3, -1, 1) and C(1, 2, 1) on it. The highest point of the ball takes, is D(2, 3, 1) as shown in the figure. Using this information answer the question.

The maximum height of the ball from the ground is

Options:

$\frac{5}{\sqrt{29}}$ units

$\frac{7}{\sqrt{29}}$ units

$\frac{6}{\sqrt{29}}$ units

$\frac{8}{\sqrt{29}}$ units

Correct Answer:

$\frac{5}{\sqrt{29}}$ units

Explanation:

Maximum point D(2, 3, 1)

so distance from place

= $\frac{|3×2+2×3+4×1-11|}{\sqrt{3^2+2^2+4^2}} = \frac{|6+6+4-11|}{\sqrt{9+4+16}}$

$= \frac{5}{\sqrt{29}}$ units