Question

if the roots of the quadratic equation X square - 4 x minus log 3 a is equals to zero a real the least value of a is-​

Answer 1

Answer:

1/81.

Explanation:

Please find the attached image.

Answer 2

Answer:

B) 1/81

Explanation:

Hey mate i know the answer

the easiest approach to solve is to see from options.

let us take 1/84

x^2-4x- log 1/84 with base 3 =0

log1/84 with base 3 =1.01 ≈ 1

x^2-4x-1=0

x=2+ square root 5, 2- square root 5

hence it is a real value

therefore the least value of a is 1/84 for which the roots of this quadratic equation are real.

NOTE- IF YOU WILL PUT 81 THEN ALSO ROOTS WILL BE REAL BUT IT IS NOT THE ANSWER BECAUSE IT IS NOT THE LEAST VALUE OF A.

THANKS

BY THE WAY, THIS QUESTION IS FROM VMC INSTITUTE MATHS WORK BOOK CLASS 11TH.