Answer:
see explanation
Step-by-step explanation:
Check the value of the discriminant
Δ = b² - 4ac
• If b² - 4ac > 0 then roots are real
• If b² - 4ac = 0 roots are real and equal
• If b² - 4ac < 0 then roots are not real
given (x - a)(x - b) = k² ( expand factors )
x² - bx - ax - k² = 0 ( in standard form )
x² + x(- a - b) - k² = 0
with a = 1, b = (- a - b), c = -k²
b² - 4ac = (- a - b)² + 4k²
For a, b, k ∈ R then (- a - b)² ≥ 0 and 4k² ≥ 0
Hence roots of the equation are always real for a, b, k ∈ R
