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Grade 12th passAlgebra

FIND THE NO OF REAL SOLUTIONS OF x^2-3|x|+2=0

Profile image of ABHISHEK VASHIST
13 Years agoGrade 12th pass
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3 Answers

Profile image of Bevkoof Singh
13 Years ago

iit should be 4

Profile image of Vikas TU
ApprovedApproved Tutor Answer13 Years ago

x^2-3|x|+2=0

Case 1: when x > 0

x2 - 3x + 2 = 0

 

x2  - 2x - x + 2 = 0

x(x-2) -1(x-2) = 0

(x-1) (x-2) = 0

x = 1 and x = 2

 

Case 2: when x < 0

x2 + 3x + 2 = 0

x2 + 2x + x + 2 = 0

x(x+2) + 1(x+2) = 0

(x+1) (x+2) = 0

x = -1 and x = -2

 

From both cases x belongs to {-1, -2, 1, 2}

Hence it has four no. of solutions.

 

PLZ  APPROVE!

Profile image of Prajwal kr
ApprovedApproved Tutor Answer13 Years ago

Take two cases:

1.x>=0:

x2-3x+2

Soln: 2 solutions.(x=2,1)

2.x<0

x2+3x+2

Solution: 2 solutions(x=-2,-1)

 

Therefore 4 solutions.