Question

Need help.. its urgent... !!
if a, b are roots of the equation px^2 + qx + r= 0, p is not equal to 0 and p,q,r are in A.P. and 1/a + 1/b = 4 , then find the value of |a-b|

Answer 1

2q = p+r

Answer 2

1/a + 1/b = 4

(a+b)/(ab) = 4

-q/r = 4

Answer 3

then use : (a-b)^2 = (a+b)^2 - 4ab

Answer 4

once you have the numerical value, take the square root to get the value of |a-b|

Answer 5

@ganeshie8 can you further explain it.. by the way thnxx... !!

Answer 6

(a-b)^2 = (a+b)^2 - 4ab
= (4ab)^2 - 4ab

Answer 7

find the value of `ab` and plug it above^

Answer 8

ab = r/p

2q = p+r
-q/r = 4
=> r/p = -1/9

Answer 9

So, ab = -1/9

Answer 10

(a-b)^2 = (a+b)^2 - 4ab
= (4ab)^2 - 4ab
= (4/9)^2 + 4/9

Answer 11

simplify and take the squareroot

Answer 12

you should get |a-b| = 2sqrt(13)/9