Identify Graph Shape: Identify the general shape of the graph for the function y=−x2. Since the coefficient of x2 is negative, the parabola opens downward.
Determine Vertex: Determine the vertex of the parabola.For the function y=−x2, the vertex is at the origin (0,0) because there is no h or k in the vertex form y=a(x−h)2+k.
Check Symmetry: Check for symmetry.The graph of y=−x2 is symmetric about the y-axis because it is an even function.
Plot Points: Plot the vertex and a few points on either side of the vertex. The vertex is at (0,0). Choosing x=1 and x=−1, we get y=−1 for both, so the points (1,−1) and (−1,−1) are on the graph. Choosing x=2 and x=−2, we get y=−4 for both, so the points (2,−4) and x=10 are on the graph.
Draw Parabola: Draw the parabola. Using the points and the knowledge that the parabola opens downward, draw a smooth curve through the points, making sure it is symmetric about the y-axis and that it continues infinitely in both directions along the x-axis.
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