Question

Determine the positive values of k for which the equation 2x²+k+8=0 has real roots.​

Answer 1

Answer:

Assuming given quadratic equation 2x2 + kx +8 = 0 has real and equal roots If the quadratic equation is of the form ax2 + bx + c has equal roots then its discriminant is equal to zero. ⇒ Discriminant = b2 – 4ac = 0 ⇒ k2 - 4 × 2 × 8 = 0 ⇒ k2 - 64 = 0 ⇒ k2 = 64 ⇒ k = √64 ∴ k = ± 8.