solv.this one on differentiation

f(x)=[x] ,x≥0

f(x)=K+[x] ,x<0,

{[.] is the greatest integer function......}

is continuous at x=0, and one root of ax^{2}+bx+c=0 exceeds the other by K,....then b^2-4ac =?

a) a b)b c)a^2 d)b^2

4 Answers

1
ith_power ·

k=1.
let the roots be p, p+1.
b^2-4ac=a^2

1
metal ·

For the function to be continuous, k=1.

So, b2 -4ac = a2

106
Asish Mahapatra ·

as f(x) is continous at x=0
at x=0- .. f(x) = K + [0-] = K-1
at x=0+... f(x) = [0+] = 0

as continous... K-1=0 ==> K=1

let one root be m and other be m+1
now, x = (-b+√b2-4ac)/2a and (-b-√b2-4ac)/2a = p and p+1

subtracting both..

b2-4ac/a = (p+1) - p = 1
So, √b2-4ac = a

1
rahul nair ·

thanxxxxxxxxx.......

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