KCET · Maths · Straight Lines
A variable line \(\frac{x}{a}+\frac{y}{b}=1\) is such that \(a+b=4\). The locus of the mid point of the portion of the line intercepted between the axes is
- A \(x+y=4\)
- B \(x+y=8\)
- C \(x+y=1\)
- D \(x+y=2\)
Answer & Solution
Correct Answer
(D) \(x+y=2\)
Step-by-step Solution
Detailed explanation
Let the coordinate of mid point of \(A B\) is \(\left(x_{1}, y_{1}\right)\).

\(
\begin{aligned}
&\Rightarrow \quad \mathrm{x}_{1}=\frac{\mathrm{a}+0}{2}, \mathrm{y}_{1}=\frac{0+\mathrm{b}}{2} \\
&\therefore \quad \mathrm{a}=2 \mathrm{x}_{1}, \mathrm{~b}=2 \mathrm{y}_{1} \\
&\text { Given, } \quad \mathrm{a}_{1}+2 \mathrm{~b}_{1}=4 \\
&\therefore \quad \mathrm{x}_{1}+\mathrm{y}_{1}=2
\end{aligned}
\)
Hence, the locus of the mid point is
\(
x+y=2
\)

\(
\begin{aligned}
&\Rightarrow \quad \mathrm{x}_{1}=\frac{\mathrm{a}+0}{2}, \mathrm{y}_{1}=\frac{0+\mathrm{b}}{2} \\
&\therefore \quad \mathrm{a}=2 \mathrm{x}_{1}, \mathrm{~b}=2 \mathrm{y}_{1} \\
&\text { Given, } \quad \mathrm{a}_{1}+2 \mathrm{~b}_{1}=4 \\
&\therefore \quad \mathrm{x}_{1}+\mathrm{y}_{1}=2
\end{aligned}
\)
Hence, the locus of the mid point is
\(
x+y=2
\)
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Maths
- If \( f(x)=\left\{\begin{array}{cc}\frac{\log _{e} x}{x-1} & ; x \neq 1 \\ k & ; x=1\end{array}\right. \) is continuous at \( x=1 \), then the value of \( k \) isKCET 2018 Easy
- \(\log \left(\sin 1^{\circ}\right) \cdot \log \left(\sin 2^{\circ}\right) \cdot \log \left(\sin 3^{\circ}\right)\) \(\ldots \log \left(\sin 179^{\circ}\right)\)KCET 2013 Easy
- Equation of the circle centred at \((4,3)\) touching the circle \(x^{2}+y^{2}=1\) externally, isKCET 2010 Medium
- The contrapositive of the statement. "If two lines do not intersect in the same plane, then they are parallel." isKCET 2023 Easy
- If \(\hat{\mathbf{i}}, \hat{\mathbf{j}}, \hat{\mathbf{k}}\) are unit vectors along the positive direction of \(\mathrm{x}, \mathrm{y}\) and \(\mathrm{z}\)-axes, then a false statement in the following isKCET 2010 Medium
- If the parametric equation of curve is given by \(x=\cos \theta+\log \tan \frac{\theta}{2}\) and \(y=\sin \theta\), then the points for which \(\frac{d y}{d x}=0\) are given byKCET 2021 Medium
More PYQs from KCET
- DNA gyrase, the enzyme that participates in the process of DNA replication, is a type ofKCET 2010 Hard
- If \(\frac{d y}{d x}+\frac{y}{x}=x^2\), then \(2 y(2)-y(1)=\)KCET 2022 Medium
- One mole of \( 4 \) gas is heated at constant pressure starting at \( 27{ }^{\circ} \mathrm{C} . \) How much energy must be added to the gas as heat to double its volume?KCET 2019 Medium
- EcoRI isKCET 2014 Easy
- How many times more intense is a \(60 \mathrm{~dB}\) sound than a \(30 \mathrm{~dB}\) sound?KCET 2008 Easy
- Two tiny spheres carrying charges \(1.8 \mu \mathrm{C}\) and \(2.8 \mu \mathrm{C}\) arc located at \(40 \mathrm{~cm}\) apart. The potential at the mid - point of the line joining the two charges isKCET 2022 Medium