Question
Mathematics Question on distance between two points
The number of real solutions of the equation |x|2 + 5|x| + 4 = 0 is
A
(A) 0
B
(B) 1
C
(C) 2
D
(D) 3
Answer
(A) 0
Explanation
Solution
Explanation:
Given: |x|2+5|x|+4=0Case I: If x≥0, then |x|=x and x2+5x+4=0 (x+1)(x+4)=0⇒x=−1,−4(<0)Thus, there is no solution of the equation when x≥0 Case ‖: If x<0, then |x|=−xThe equation is x2−5x+4=0⇒(x−1)(x−4)=0⇒x=1,4(>0)Thus, there is no solution of the equation when x<0