for what value of k is 3 a zero of polynomial 2xsquare +x +k
Answers
Answered by
12
Answer:
The polynomial is :
2x² + x + k
Suppose, 3 is zero of polynomial for some value of k, then
2x² + x + k = 0
∴2(3)² + 3 + k = 0 (Putting x = 3)
∴2*9 + 3 + k = 0
∴18 + 3 + k = 0
∴21 + k = 0
∴k = -21
Thus, for k = -21, 3 is a zero of the polynomial.
Step-by-step explanation:
Answered by
4
We know that if
x
=
a
x=a is zero polynomial, and then x - a is a factor of f(x)
Since 3 is zero of f (x)
Therefore x - 3 is a factor of f(x)
Now, we divide
f
(
x
)
=
2
x
2
+
x
+
k
f(x)=2x2+x+k by
g
(
x
)
=
x
−
3
g(x)=x-3 to find the value of k
Step-by-step explanation:
Now, remainder = 0
k
+
21
=
0
k+21=0
k
=
−
21
k=-21
Hence, the value of k is = -21
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