ROOTS

LETA,B,C ε R SUCH THAT 4A+2B+C=0 AND AB>0 THEN EQUATION AX2+BX+C=0 HAS WHICH ROOTS REAL,COMPLEX

7 Answers

1
skygirl ·

x=+2 is a root... which is obviously real...

1
skygirl ·

x=-1 is also a root.. which is also real..

1
ith_power ·

how come x=-1?????

62
Lokesh Verma ·

4A+2B+C=0
put C= -(4A+2B)

AX2+BX-(4A+2B)=0

A(X2-4) + B(X-2) = 0
A(X-2)(X+2) + B(X-2) = 0
(X-2){ A(X+2) + B } = 0

X=2 is one root

X=-2+B/A is another root..

62
Lokesh Verma ·

u are right ith power..

-1 is not!

62
Lokesh Verma ·

sum of the roots is B/A

since AB is +ve B/A is positive..

so the roots are real!

1
skygirl ·

no -1 is not...
i got it by mistake...

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