Question

If the product of zeroes of the quadratic polynomial $f\left(x\right)=x^2-4x+k$ is $3,$ find the value of $K$

Answer 1

Zeros of a quadratic equation are its roots.

Comparing $f\left(x\right)=x^2-4x+k$ with the standard equation $f\left(x\right)=x^2+px+q$,

we get,

$p=-4$

$q=k$

if $\alpha$ & $\beta$ are the roots of the given quadratic equation,

$\alpha +\beta =-p$

$\alpha \times \beta =q$

but,

$\alpha \times \beta =3$ {given}

$\therefore k=3$