Chapter 9 Quadratic Relations and Conic Sections - 9.2 Graph and Write Equations of Parabolas - 9.2 Exercises - Skill Practice - Page 623: 15

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The equation in standard form: $5x^2=-15y\\x^2=-3y$ Identify the focus, directrix, and axis of symmetry. The equation has the form $x^2=4py$ where $p=-0.75$. The focus is $(0,-0.75)$. The directrix is $x =-p=0.75$. Because $y$ is squared, the axis of symmetry is the x-axis. Find some values and plot points: $x=1 \rightarrow y=\pm 1.73\\x=-2 \rightarrow y=\pm 2.45\\x=-3 \rightarrow y=\pm 3\\x=-4 \rightarrow y=\pm 3.46\\x=-5 \rightarrow y=\pm 3.87$