Question

solve this question fast with explanation​

Answer 1

Step-by-step explanation:

Given Polynomial is -

f(x) = 2x² + 4x + k

Given In Question -

α² + β² + αβ = 21/4 ......(i)

According To Question -

We Know αβ = c/a

and α + β = -b/a

then αβ = k/2

and α + β = -4/2 = -2

Puting values in equation (i) -

(-2)² + k/2 = 21/4

4 + k/2 = 21/4

k/2 = 21/4 - 4

k/2 = 5/4

k = 5×2/4

k = 10 / 4

Then K Should Be -

5 / 2