Sign in
ui-button
ui-button
Both the roots of the given equation. \( \Large \left(x-a\right) \left(x-b\right)+ \left(x-b\right) \left(x-c\right)+ \left(x-c\right) \left(x-a\right)=0 \) are always
A) positive
B) negative
C) real
D) imaginary
Correct answer:
C) real
Description for Correct answer:
Given equation:
\( \Large \left(x-a\right) \left(x-b\right)+ \left(x-b\right) \left(x-c\right)+ \left(x-c\right) \left(x-a\right)=0 \)
\( \Large 3x^{2}-2 \left(a+b+c\right)x+ \left(ab+bc+ca\right)=0 \)
Now, \( \Large BZ-4AC=4\left[ \left(a+b+c+\right)^{2}-3 \left(ab+bc+ca\right) \right] \)
= \( \Large 4 \left(a^{2}+b^{2}+c^{2}-ab-bc-ac\right) \)
= \( \Large 2\{ \left(a-b\right)^{2}+ \left(b-c\right)^{2}+ \left(c-a\right)^{2} \}\ge 0 \)
Hence, both roots are always real.
Please provide the error details in above question
Report Error
Recent Activities
General Knowledge
More questions and answers on- General Knowledge
Aptitude
More questions and answers on- Aptitude
Number System
More questions and answers on- Number System
Time and Distance
More questions and answers on- Time and Distance
Average
More questions and answers on- Average
Time and work
More questions and answers on- Time and work
Simple and compound interest
More questions and answers on- Simple and compound interest
Mensuration
More questions and answers on- Mensuration
Number series
More questions and answers on- Number series
Pipes and Cisterns
More questions and answers on- Pipes and Cisterns
Linear Equations
More questions and answers on- Linear Equations
Quadratic Equations
More questions and answers on- Quadratic Equations
Simplification
More questions and answers on- Simplification
Approximation
More questions and answers on- Approximation
Word problems
More questions and answers on- Word problems