Mathematics · Quadratic Equations

JEE Main 2024 — 5 April, Shift 1 — Question 29

The number of distinct real roots of the equation ∣x∣∣x+2∣−5∣x+1∣−1=0|x||x+2|-5|x+1|-1=0 is \qquad

Answer: 3

Numerical answer — enter this value.

Step-by-step solution

Case-1 :x≥0\mathrm{x} \geq 0

x2+2x−5x−5−1=0x^{2}+2 x-5 x-5-1=0

x2−3x−6=0x^{2}-3 x-6=0

x=3±9+242=3±332\mathrm{x}=\frac{3 \pm \sqrt{9+24}}{2}=\frac{3 \pm \sqrt{33}}{2}

One positive root

CASE -2 :−1≤x<0-1 \leq \mathrm{x}<0

−x2−2x−5x−5−1=0-x^{2}-2 x-5 x-5-1=0

x2+7x+6=0x^{2}+7 x+6=0

(x+6)(x+1)=0(x+6)(x+1)=0

x=−1\mathrm{x}=-1

one root in range

CASE-3 :−2≤x<−1-2 \leq \mathrm{x}<-1

x2−2x+5x+5−1=0x^{2}-2 x+5 x+5-1=0

x2−3x−4=0x^{2}-3 x-4=0

(x−4)(x+1)=0(x-4)(x+1)=0

No root in range

Case-4 :x<−2\mathrm{x}<-2

x2+7x+4=0\mathrm{x}^{2}+7 \mathrm{x}+4=0

x=−7±49−162=7±332x=\frac{-7 \pm \sqrt{49-16}}{2}=\frac{7 \pm \sqrt{33}}{2}

one root in range

Total number of distinct roots are 3

Answer key and solution verified before publishing.

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Exam
JEE Main 2024
Subject
Mathematics
Chapter
Quadratic Equations
Topic
Nature of Roots of Quadratic Equation
The number of distinct real roots of the equation x x+2 -5 x+1 -1=0 is | JEE Main 2024 PYQ with Solution · DhiX AI