Find the least positive value of k for which the equation has real roots.

For a quadratic equation, ax2 + bx + c = 0,


D = b2 – 4ac


If D ≥ 0, roots are real



D = k2 – 16


Thus, k2 – 16 ≥ 0


k ≥ 4 or k ≤-4


Thus, least positive value of k is 4.


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