Question

The value of k for which the quadratic equation 2x^2+kx+2=0 has equal roots, is

Answer 1

Answer:

the answer is plus or minus 4

Step-by-step explanation:

since its given that the above equation has real and equal roots. substitute it values in the formula b² - 4ac

where b =k a=2 c =2

you get it as: k²- 4×2×2=0

k²-16=0

k²=16

k = plus or minus 4

hope this helps you :)

Answer 2

Step-by-step explanation:

The condition for equal roots is

b^2 - 4ac

2x^2+k x+2 = 0

ax^2+b x +c = 0

a = 2

b = k

c = 2

substitute these values in b^2-4ac

k^2 - 4 × 2×2 = 0

k ^2 - 4×4 = 0

k ^2 - 16 = 0

k ^2 = 16

k = √16

k = ± 4

Therefore the value of k is ± 4