Discussion
The number of real roots of the equation 2x4 + 5x2 + 3 = 0 is
Answer: C
The equation has 0 real roots.
Put y = x2, which turns it into a quadratic in y:
\[ \begin{aligned} 2y^{2} + 5y + 3 &= 0 \\ (2y + 3)(y + 1) &= 0 \\ y &= -1 \text{ or } -\tfrac{3}{2} \end{aligned} \]
Both values are negative, and x2 cannot be negative for real x, so there are no real roots. A quicker check: every term on the left is positive for real x, so the sum can never be 0.
No comment is present. Be the first to comment.
Loading…
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development