Question

If alpha and beta be the zeroes of the quadratic polynomial 2x²-kx+7 since that alpha²+beta²=1/2, alphaxbeta = 23/2 find value of k​

Answer 1

Answer:

k=±√30

Step-by-step explanation:

2x²-kx+7

αβ=7/2 and α+β=-(-k/2)=k/2

α²+β²=1/2

(α+β)²-2αβ=1/2

(k/2)²-2(7/2)=1/2

k²/4-7=1/2

k²/4=7+1/2=15/2

k²=15/2*4=30

k=±√30