If all real values of obtained from the equation are non-positive, then
Step 1:Reduce the given equation into a quadratic equation.
We have given an equation , and.
We can rewrite the given equation as
let us take
Step 2: Find the discriminant of the above quadratic equation.
Step 3: Applying the quadratic formula in the above quadratic equation.
Step 4: Apply the conditions to find the interval, in which ‘a’ lies.
Hence, the correct option is.