Question:
Find the zeros of the polynomial $x^{2}-3 x-m(m+3)$
Solution:
$f(x)=x^{2}-3 x-m(m+3)$
By adding and subtracting mx, we get
$f(x)=x^{2}-m x-3 x+m x-m(m+3)$
$=x[x-(m+3)]+m[x-(m+3)]$
$=[x-(m+3)](x+m)$
$f(x)=0 \Rightarrow[x-(m+3)](x+m)=0$
$\Rightarrow[x-(m+3)]=0$ or $(x+m)=0$
$\Rightarrow x=m+3$ or $x=-m$
So, the zeros of f(x) are −m and m + 3.
Click here to get exam-ready with eSaral
For making your preparation journey smoother of JEE, NEET and Class 8 to 10, grab our app now.