Question

Without graphing ,find where each parabola crosses the x-axis.a) y=x^-2x-3

Answer 1

When the parabola crosses the x-axis the parabola "intersects" or touches the x-axis, and therefore is an x-intercept, and we can get those by simply setting y = 0 and getting "x".

$\bf y=x^2-2x-3\implies \stackrel{y}{0}=x^2-2x-3\implies 0=(x-3)(x+1) \\\\\\ x= \begin{cases} 3\\ -1 \end{cases}$