MCQ
A line $L$ passes through the points $(1, 1)$ and $(2, 0)$ and another line $L'$ passes through $\left( {\frac{1}{2},0} \right)$ and perpendicular to $L$. Then the area of the triangle formed by the lines $L,L'$ and $y$- axis, is
  • A
    $15\over8$
  • B
    $25\over4$
  • C
    $25\over8$
  • $25\over16$

Answer

Correct option: D.
$25\over16$
d
(d) Here $L \equiv x + y = 2$and $L' \equiv 2x - 2y = 1$.

Equation of $y$-axis is $x = 0$

Hence the vertices of the triangle are $A(0,\,2),B\left( {0, - \frac{1}{2}} \right)$ and $C\left( {\frac{5}{4},\frac{3}{4}} \right)$. Therefore, the area of the triangle is $\frac{1}{2}\left| {\,\begin{array}{*{20}{c}}0&2&1\\0&{ - \frac{1}{2}}&1\\{\frac{5}{4}}&{\frac{3}{4}}&1\end{array}\,} \right| = \frac{{25}}{{16}}$.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

If $\alpha $ and $\beta $, $\alpha $ and $\gamma $, $\alpha $ and $\delta $ are the roots of the equations $a{x^2} + 2bx + c = 0$, $2b{x^2} + cx + a = 0$ and $c{x^2} + ax + 2b = 0$ respectively, where $a,b$ and $c$ are positive real numbers, then $\alpha + {\alpha ^2}$=
A unit vector in the plane of the vectors $2i + j + k,\,$ $\,i - j + k$ and orthogonal to $5i + 2j + 6k$ is
The function $f(x) = 1 - {e^{ - {x^2}/2}}$ is
If a matrix  $A$  is such that $3{A^3} + 2{A^2} + 5A + I = 0,$ then its inverse is
The equations of the directrices of the ellipse $16{x^2} + 25{y^2} = 400$ are
The solution of the differential equation $xy\frac{{dy}}{{dx}} = \frac{{(1 + {y^2})(1 + x + {x^2})}}{{(1 + {x^2})}}$ is
Let $P$ and $Q$ be any points on the curves $( x-1)^{2}+(y+1)^{2}=1$ and $y=x^{2}$, respectively. The distance between $P$ and $Q$ is minimum for some value of the abscissa of $P$ in the interval
A coin is tossed $3$ times. The probability of getting exactly two heads is
For $0<\mathrm{c}<\mathrm{b}<\mathrm{a}$, let $(\mathrm{a}+\mathrm{b}-2 \mathrm{c}) \mathrm{x}^2+(\mathrm{b}+\mathrm{c}-2 \mathrm{a}) \mathrm{x}$ $+(c+a-2 b)=0$ and $\alpha \neq 1$ be one of its root. Then, among the two statements

$(I)$ If $\alpha \in(-1,0)$, then $\mathrm{b}$ cannot be the geometric mean of $\mathrm{a}$ and $\mathrm{c}$

$(II)$ If $\alpha \in(0,1)$, then $\mathrm{b}$ may be the geometric mean of $a$ and $c$

Inverse of the matrix $\left[ {\begin{array}{*{20}{c}}{\cos 2\theta }&{ - \sin 2\theta }\\{\sin 2\theta }&{\cos 2\theta }\end{array}} \right]$ is