- Exam
- JEE Main
- Year
- 2022
- Date
- 27 July
- Shift
- Morning Shift
- Subject
- Mathematics
- Chapter
- Straight Lines
JEE Main 2022 · 27 July · Morning Shift · Mathematics · Straight Lines
Let A (1, 1), B (- 4, 3), C(- 2, - 5) be vertices of a triangle...
Let \left(1, 1\right), B be vertices of a triangle be a point on side , and and be the areas of triangle and .
Respectively.
If , then the area enclosed by the lines and the -axis is
Options
- A
- B
- C
- D
Correct answer
C.
Step-by-step solution
Plotting the given value in diagram we have,
Now let be a point on , so area formed by will be,
{\Delta}_{1} = \dfrac{1}{2}\left|\begin{cases}x & y & 1 \\ 1 & 1 & 1 \\ - 4 & 3 & 1\end{cases}\right| = \dfrac{1}{2}\left(- 2x - 5y + 7\right)
And area of triangle formed by will be, {\Delta}_{2} = \dfrac{1}{2}\left|\begin{cases}1 & 1 & 1 \\ - 4 & 3 & 1 \\ - 2 & - 5 & 1\end{cases}\right| = \dfrac{36}{2}
Given
Equation of by two point form will be
Solving equation \left(1\right) we get,
Point
Now equation of will be
,
So intercept will be point and similarly from we get
So Area of triangle