Question

if alpha and beta are the roots of the equation ax^2 +bx+c=0,alpha.beta=3 and a,b,c are in A.P. then alpha + beta is equal to ?

Answer 1

If alpha and beta are the roots of the equation ax^2 +bx+c=0 then

alpha+beta=-b/a

alpha.beta=c/a=3(given)==>c=3a

Also given a,b,c are in A.P then 2b=a+c
so, b= a+c/ 2

b=a+3a/2

b=4a/2

b=2a

Now,

alpha+beta= -b/a

= -2a/a

= -2


so alpha + beta= -2

Hope this helps you!!!;