AP EAMCET2012MathematicsQuadratic Equation
In P Q R, R= 4 , ( P 3 ), ( Q 3 ) are the roots of the equation a x^2+b x+c=0 , then
Options
- Aa+b=c
- Bb+c=0
- Ca+c=0
- Db=c
Correct answer
A. a+b=c
Step-by-step solution
Given, R= 4 Also, P+Q+R= array ll & P+Q+ 4 = & P+Q= 3 4 & P 3 + Q 3 = 4 & ( P 3 + Q 3 )= ( 4 ) & P 3 + Q 3 1- P 3 Q 3 =1 array Since, P 3 and Q 3 are the roots of the equation a x^2+b x+c=0 . P 3 + Q 3 =- b a and P 3 Q 3 = c a From Eq. (i), - b a 1- c a =1 array ll & -b a-c =1 & a+b=c array