(i) x² + 6x – 4 = 0

Solution:

Let p(x) = x² + 6x – 4,

It’s clearly seen that p(x) = x² + 6x – 4 is a quadratic polynomial. Thus, the given equation is a quadratic equation.

(ii) √3x² – 2x + 1/2 = 0

Solution:

Let p(x) = √3x² – 2x + 1/2,

It’s clearly seen that p(x) = √3x² – 2x + 1/2 having real coefficients is a quadratic polynomial. Thus, the given equation is a quadratic equation.