I am having trouble solving this equation. It reads…
Given that the equation $kx^2+12x+k = 0$, where $k$ is a positive constant, has equal roots, find the value of $k$.
I am not sure where to start as there is two unknown variables, $k$ and $x$ so I don't think I can factorise. Any help would be much appreciated.
Best Answer
Hint: as $k>0$ is fixed, this equation is a second degree equation in the variable $x$. There is one root iff the discriminant is 0. In you case: $$ 12^2- 4\times k\times k = 0 $$