Use app×
Join Bloom Tuition
One on One Online Tuition
JEE MAIN 2025 Foundation Course
NEET 2025 Foundation Course
CLASS 12 FOUNDATION COURSE
CLASS 10 FOUNDATION COURSE
CLASS 9 FOUNDATION COURSE
CLASS 8 FOUNDATION COURSE
0 votes
3.9k views
in Quadratic Equations by (31.2k points)
closed by

Write the set of values of 'a' for which the equation x2 + ax – 1 = 0 has real roots.

1 Answer

+1 vote
by (30.8k points)
selected by
 
Best answer

Consider x2 + ax – 1 = 0,For the quadratic equation to have real roots D ≥ 0

Here a = 1, b = a and c = 1

In the given equation D = a2 – 4 ≥ o

⇒ a2 ≥ 4

So for all the real values of ‘a’ which are greater than or equal to 2 and – 2 the equation will have the real roots.

Welcome to Sarthaks eConnect: A unique platform where students can interact with teachers/experts/students to get solutions to their queries. Students (upto class 10+2) preparing for All Government Exams, CBSE Board Exam, ICSE Board Exam, State Board Exam, JEE (Mains+Advance) and NEET can ask questions from any subject and get quick answers by subject teachers/ experts/mentors/students.

...