Reflect the graph of $y=x^2$ with respect to $x$ axis to get the graph of $y=-x^2$ in the figure below
Work Step by Step
We can start with the graph of $y=x^2$. The graph of $y=-x^2$ is obtained from here by reflecting this graph with respect to $x$ axis since every value of the function will change its sign. This is done in the figure below.