We can use the 'discriminant' to show how many roots there are, if any: \({b^2} - 4ac\textgreater0\) means there are two roots \({b^2} - 4ac = 0\) means there is one root (because the turning ...

If \(kx^{2}+5x-\frac{5}{4}=0\) has equal roots, then \(b^2-4ac=0\). \(a=k\), \(b=5\) and \(c= - \frac{5}{4}\). \(b^2-4ac=0\) \(5^2 -4\times k \times - \frac{5}{4}=0 ...