The quadratic equations x2−6x + a = 0 and x2−cx + 6 = 0 have one root in common. The other roots of the first and second equations are integers in the ratio 4:3. Then the common root is
see full answer
Your Exam Success, Personally Taken Care Of
1:1 expert mentors customize learning to your strength and weaknesses – so you score higher in school , IIT JEE and NEET entrance exams.
An Intiative by Sri Chaitanya
a
1
b
4
c
3
d
2
answer is D.
(Unlock A.I Detailed Solution for FREE)
Best Courses for You
JEE
NEET
Foundation JEE
Foundation NEET
CBSE
Detailed Solution
The given quadratic equations are x2−6x + a = 0 …… ( 1 ) and x2−cx + 6 = 0 ….. ( 2 )Given that one root is common, it is consider as α And the other roots of the first and second equations are integers in the ratio 4 : 3∴ the roots are α,4β,α,3β From Eq.( 1 ) & Eq.( 2 ) consider product of the roots ⇒4αβ=a and 3αβ=6 ∴αβ=2, a=8 From ( 1 ): x2−6x + 8 = 0 ⇒x2−4x−2x+8=0 ⇒(x−2)(x−4)=0 ∴x=2,4 ….. ( 3 )If take 2 is common root then Eq. ( 2 ) will be x2−cx + 6 = 0 ⇒(2)2−c(2)+6=0 ⇒c=5 . If take 4 is common root then Eq.( 2 )is not satisfies.∴ Eq. ( 2 ) ⇒ x2−5x+6=0 ⇒x2−3x−2x+6=0 ⇒(x−3)(x−2)=0 ∴x=3,2 ….. ( 4 )From Eq.( 3 ) & Eq.( 4 )∴ common root =2
The quadratic equations x2−6x + a = 0 and x2−cx + 6 = 0 have one root in common. The other roots of the first and second equations are integers in the ratio 4:3. Then the common root is