Find the number of integral roots of the following quadratic equation :
Note: is an integer
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
Let the roots of the given quadratic equation be a and b .
By Vieta's formula :
a + b = − 7 and a b = − 1 4 ( q 2 + 1 )
Note that from first condition, if one of the roots is integral , the other one must be integral.
Now, from second condition , we note that a b < 0 . WLOG let us assume that a > 0 and b < 0 . Now set c = − b so that c > 0 and the new equations become :
c − a = 7 and c a = 1 4 ( q 2 + 1 )
Hence, the given quadratic equation can never have any integral roots.