Question:
The zeros of the polynomial $x^{2}-\sqrt{2} x-12$ are
(a) $\sqrt{2},-\sqrt{2}$
(b) $3 \sqrt{2},-2 \sqrt{2}$
(c) $-3 \sqrt{2}, 2 \sqrt{2}$
(d) $3 \sqrt{2}, 2 \sqrt{2}$
Solution:
(b) $3 \sqrt{2},-2 \sqrt{2}$
Let $f(x)=x^{2}-\sqrt{2} x-12=0$
$=>x^{2}-3 \sqrt{2} x+2 \sqrt{2} x-12=0$
$=>x(x-3 \sqrt{2})+2 \sqrt{2}(x-3 \sqrt{2})=0$
$=>(x-3 \sqrt{2})(x+2 \sqrt{2})=0$
$=>x=3 \sqrt{2}$ or $x=-2 \sqrt{2}$
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.