Question

One root of the equation ax2+bx+c=0 be the double of the othe then pove 2b2=9c

Answer 1

Answer:

correction :- prove 2b² = 9ac

Step-by-step explanation:

let one root be alfa then other root will

be 2alfa according to the question.

we know that

alfa+ 2alfa = 3alfa= -b/a

=> 9alfa² = b²/a²

=> alfa²= b²/9a².........(1)

alfa×2alfa= 2alfa²= c/a

=> alfa² = c/2a............(2)

from (1) and (2),

=> b²/9a² = c/2a

=> 2b²= 9ac

Proved