JEE Main 201815 AprilMorning ShiftOnline
- Exam
- JEE Main
- Year
- 2018
- Date
- 15 April
- Shift
- Morning Shift
- Mode
- Online
- Subject
- Mathematics
- Chapter
- Determinants
JEE Main 2018 · 15 April · Morning Shift · Online · Mathematics · Determinants
Let S be the set of all real values of k for which the system of...
Let be the set of all real values of which the system of linear equations
has a unique solution. Then is
Options
- Aan empty set
- Bequal to
- Cequal to
- Dequal to
Correct answer
B. equal to
Step-by-step solution
The system of linear equations is:
\begin{aligned}
&x+y+z=2 \\
&2 x+y-z=3 \\
&3 x+2 y+k z=4
\end{aligned}
As, system has unique solution.
\begin{aligned}
&\text{ So, }\left|\begin{array}{ccc}
1 & 1 & 1 \\
2 & 1 & -1 \\
3 & 2 & k
\end{array}\right| \neq 0 \\
&\Rightarrow k+2-(2 k+3)+1 \neq 0 \\
&\Rightarrow k \neq 0
\end{aligned}$$k \in R-\{0\} \equiv S$