Target Exam

CUET

Subject

Section B1

Chapter

Three-dimensional Geometry

Question:

If the equation of a line is $x = ay + b, z = cy + d$, then find the direction ratios of the line and a point on the line.

Options:

Direction Ratios: $(a, 1, c)$; Point: $(b, 0, d)$

Direction Ratios: $(1, a, c)$; Point: $(0, b, d)$

Direction Ratios: $(a, b, c)$; Point: $(1, 0, 1)$

Direction Ratios: $(b, 1, d)$; Point: $(a, 0, c)$

Correct Answer:

Direction Ratios: $(a, 1, c)$; Point: $(b, 0, d)$

Explanation:

The correct answer is Option (1) → Direction Ratios: $(a, 1, c)$; Point: $(b, 0, d)$ ##

$x = ay + b ⇒\frac{x - b}{a} = y$

$z = cy + d ⇒\frac{z - d}{c} = y$

$∴$ Equation of the line:

$\frac{x - b}{a} = \frac{y - 0}{1} = \frac{z - d}{c}$

$\textbf{Direction ratios of the line}: (a, 1, c)$

$\textbf{Point on the line}:(b, 0, d)$