Question

for what value of k,3 is zero of the polynomial 2x square + x + k

Answer 1

Hey friend, ☺ here is your answer ____________________________
It is given that 3 is a zero of the polynomial, therefore 3 can make the whole polynomial equal to zero.
So, p(3) = 0
p(x) = 2x^2 + x + k
p(3) = 2(3)^2 + 3 + k
0 = 2 × 3 × 3 + 3 + k
0 = 18 + 3 + k
k = -21

Hope this helps you........

Answer 2

Hey Mate

your answer is ---


Given, f(x) = 2x^2+x+k

since, 3 is a zero of f(x)

so, f(3)=0

=> 2×3^2+3+k = 0

=> 18 + 3+ k = 0

=> k = -21


===================
HOPE IT HELPS YOU
===================