Example

Graphing x=−4(y+2)2+4x = -4(y+2)^2 + 4

To graph the horizontal parabola x=−4(y+2)2+4x = -4(y+2)^2 + 4 using its properties, first identify the constants aa, hh, and kk. Here, a=−4a = -4, h=4h = 4, and k=−2k = -2. Since aa is negative, the parabola opens to the left. The axis of symmetry is the horizontal line y=−2y = -2. The vertex is (4,−2)(4, -2). To find the xx-intercept, substitute y=0y = 0: x=−4(0+2)2+4=−4(4)+4=−12x = -4(0+2)^2 + 4 = -4(4) + 4 = -12. The xx-intercept is (−12,0)(-12, 0). The point symmetric to (−12,0)(-12, 0) across the axis of symmetry is (−12,−4)(-12, -4). To find the yy-intercepts, set x=0x = 0: 0=−4(y+2)2+40 = -4(y+2)^2 + 4, which gives 1=(y+2)21 = (y+2)^2. Solving yields y+2=±1y+2 = \pm 1, so y=−1y = -1 and y=−3y = -3. The yy-intercepts are (0,−1)(0, -1) and (0,−3)(0, -3). Plot these points to complete the graph.

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Updated 2026-06-05

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