Question

write the set value of k for which quadratic equation 2x^2 + kx + 8 =0 has real root

Answer 1

Hi ,

2x² + kx + 8 = 0 compare this

quadratic equation with ax²+bx +c = 0

a = 2 , b = k , c = 8

It is given that , the equation has

real roots ,

Discreaminant = D ≥ 0

b² - 4ac ≥ 0

k² - 4 × 2 × 8 ≥ 0

k² ≥ 64

k ≥ ± √64

k ≥ ± 8

I hope this helps you.

: )

Answer 2

Answer:

k = 8

Step-by-step explanation:

given equation : 2x²+kx+8 which is in the form of ax²+bx+c=0

so, a=2, b=k, c=8

D=√b²-4ac

• k²-√4×2×8
• k² - √ 64
• k ± √64
• k = ± 8