Mathematics · Straight lines

JEE Main 2024 — 31 January, Shift 2 — Question 21

Let A(−2,−1),B(1,0),C(α,β)A(-2,-1), B(1,0), C(\alpha, \beta) and D(γ,δ)D(\gamma, \delta) be the vertices of a parallelogram ABCD . If the point C lies on 2x−y=52 \mathrm{x}-\mathrm{y}=5 and the point D lies on 3x−2y=63 \mathrm{x}-2 \mathrm{y}=6, then the value of ∣α+β+γ+δ∣|\alpha+\beta+\gamma+\delta| is equal to \qquad .

Answer: 32

Numerical answer — enter this value.

Step-by-step solution

P≡(α−22,β−12)≡(γ+12,δ2)\mathrm{P} \equiv\left(\frac{\alpha-2}{2}, \frac{\beta-1}{2}\right) \equiv\left(\frac{\gamma+1}{2}, \frac{\delta}{2}\right)

α−22=γ+12\frac{\alpha-2}{2}=\frac{\gamma+1}{2} and β−12=δ2\frac{\beta-1}{2}=\frac{\delta}{2} ⇒α−γ=3….(1),β−δ=1….(2)\Rightarrow \alpha-\gamma=3 \ldots .(1), \quad \beta-\delta=1\ldots .(2)

Also, (γ,δ)(\gamma, \delta) lies on 3x-2y=6 $$$\begin{gathered}3 \gamma-2 \delta=6 \end{gathered}$$and(\alpha, \beta)liesonlies on2 x-y=5$

⇒2α−β=5….(4)\Rightarrow 2 \alpha-\beta=5 \ldots .(4)

Solving (1), (2), (3), (4) α=−3,β=−11,γ=−6,δ=−12\alpha=-3, \beta=-11, \gamma=-6, \delta=-12

∣α+β+γ+δ∣=32|\alpha+\beta+\gamma+\delta|=32

Solution figure

Answer key and solution verified before publishing.

Practise Straight lines

Start with this question, then two more from the same chapter — with a tutor that explains every step. Free.

Exam
JEE Main 2024
Subject
Mathematics
Chapter
Straight lines
Topic
Various forms of lines