Given: L passes through ( 3 , − 2 ) \text{Given: } L \text{ passes through } (3,\, -2) Given: L passes through ( 3 , − 2 )
L makes 60 ∘ with 3 x + y = 1 L \text{ makes } 60^\circ \text{ with } \sqrt{3}x + y = 1 L makes 6 0 ∘ with 3 x + y = 1
L intersects the x -axis L \text{ intersects the } x\text{-axis} L intersects the x -axis
To find: the equation of L \text{To find: the equation of } L To find: the equation of L
(from the four given options) \text{(from the four given options)} (from the four given options)
1. slope of the given line 1.\ \text{slope of the given line} 1. slope of the given line
2. angle formula for L 2.\ \text{angle formula for } L 2. angle formula for L
3. x -axis condition, then the equation 3.\ x\text{-axis condition, then the equation} 3. x -axis condition, then the equation
3 x + y = 1 ⇒ y = − 3 x + 1 \sqrt{3}x + y = 1 \ \Rightarrow \ y = -\sqrt{3}x + 1 3 x + y = 1 ⇒ y = − 3 x + 1
m 1 = − 3 m_1 = -\sqrt{3} m 1 = − 3
tan θ = ∣ m 2 − m 1 1 + m 1 m 2 ∣ \tan\theta = \left|\dfrac{m_2 - m_1}{1 + m_1 m_2}\right| tan θ = 1 + m 1 m 2 m 2 − m 1
3 = ∣ m 2 + 3 1 − 3 m 2 ∣ \sqrt{3} = \left|\dfrac{m_2 + \sqrt{3}}{1 - \sqrt{3}\,m_2}\right| 3 = 1 − 3 m 2 m 2 + 3
m 2 + 3 = 3 − 3 m 2 m_2 + \sqrt{3} = \sqrt{3} - 3m_2 m 2 + 3 = 3 − 3 m 2
4 m 2 = 0 ⇒ m 2 = 0 4m_2 = 0 \ \Rightarrow \ m_2 = 0 4 m 2 = 0 ⇒ m 2 = 0
m 2 + 3 = − 3 + 3 m 2 m_2 + \sqrt{3} = -\sqrt{3} + 3m_2 m 2 + 3 = − 3 + 3 m 2
− 2 m 2 = − 2 3 ⇒ m 2 = 3 -2m_2 = -2\sqrt{3} \ \Rightarrow \ m_2 = \sqrt{3} − 2 m 2 = − 2 3 ⇒ m 2 = 3
m 2 = 0 or m 2 = 3 m_2 = 0 \quad \text{or} \quad m_2 = \sqrt{3} m 2 = 0 or m 2 = 3
inclination of given line = 120 ∘ \text{inclination of given line} = 120^\circ inclination of given line = 12 0 ∘
θ L = 60 ∘ or 180 ∘ ⇒ m 2 = 3 or 0 \theta_L = 60^\circ \text{ or } 180^\circ \ \Rightarrow \ m_2 = \sqrt{3} \text{ or } 0 θ L = 6 0 ∘ or 18 0 ∘ ⇒ m 2 = 3 or 0
m 2 = 0 ⇒ y = − 2 (parallel to x -axis) ⇒ discard m_2 = 0 \Rightarrow y = -2 \ \text{(parallel to } x\text{-axis)} \Rightarrow \text{discard} m 2 = 0 ⇒ y = − 2 (parallel to x -axis) ⇒ discard
y − ( − 2 ) = 3 ( x − 3 ) y - (-2) = \sqrt{3}\,(x - 3) y − ( − 2 ) = 3 ( x − 3 )
y + 2 = 3 x − 3 3 y + 2 = \sqrt{3}x - 3\sqrt{3} y + 2 = 3 x − 3 3
y − 3 x + 2 + 3 3 = 0 y - \sqrt{3}x + 2 + 3\sqrt{3} = 0 y − 3 x + 2 + 3 3 = 0
Answer: (2) y − 3 x + 2 + 3 3 = 0 \boxed{\text{Answer: (2)}\ \ y - \sqrt{3}x + 2 + 3\sqrt{3} = 0} Answer: (2) y − 3 x + 2 + 3 3 = 0