if one zero of the polynomial 2xsquare – 5x – (2k+1 ) is twice the other, then find both the zeroes and the value of k
Answers
Answered by
0
Let, p(x)=2x²-5x-(2k+1)--------(1)
Also let, α be one root of (1).
Then the other root will be 2α.
α+2α=-(-5)/2
⇒ 3α=5/2
⇒ α=5/6
Again, α×2α=-(2k+1)/2
⇒ 2α²=-(2k+1)/2
⇒ -(2k+1)/2=2×(5/6)²
⇒ -(2k+1)=4×25/36
⇒ -2k-1=25/9
⇒ -2k=25/9+1
⇒ -2k=34/9
⇒ k=-34/9×1/2
⇒ k=-17/9 Ans.
Similar questions