Question

If one of the zeros of the quadratic polynomial $2x^2+px+4$ is 2, find the other zero. Also find the value of p.

• A. $p=-1$, other zero $=1$
• B. $p=-2$, other zero $=1$
• C. $p=-6$, other zero $=1$
• D. $p=-7$, other zero $=1$

Answer 1

The correct option is C $p=-6$, other zero $=1$

We know that for a quadratic polynomial $a{x}^2+bx+c$,

product of the zeros=$\frac{c}{a}$

Here,quadratic polynomial is $2x^2+px+4$

One root is $2$

Let the other root be $a$

Therefore,

$2\times a=\frac{4}{2}$

$=>a=1$

Therefore,

The other zero is $1$

Also, sum of the zeros =$\frac{-b}{a}$

$=>1+2=\frac{-p}{2}$

$=>3\times 2=-p$

$=>p=-6$

Therefore,

$p=-6$ , other root$=1$