Question 1023627
.
For what value of the constant k does the quadratic 2x^2 - 5x + k= 0 have a double root?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


<pre>
Calculate the discriminant d = {{{b^2 - 4ac}}} = (-5)^2 - 4*2*k = 25 - 8k.

The double root will happen when the discriminant is zero: d = 0.

It gives k = {{{25/8}}}.
</pre>