CONIC SECTIONS Graphing Parabolas (Page 1 of 3)

Let's graph the parabola x = (1/16)(y-4)^2-4. Because a parabola having an axis of symmetry parallel to the x-axis is not a function, it cannot be graphed in function mode as a single curve. We must first isolate y:
 y = 4+-4sqrt(x+4). In doing so, we are representing the parabola as the union of two functions. The function with the addition will be the upper half-parabola, and the function with the subtraction will be the lower half-parabola. Enter these functions separately as Y1 and Y2.

 Y= key. (Clear any previous functions)

 4 Plus key. 4 2nd Square root key. X,T,theta,n key. Plus key. 4 Right parenthesis key. ENTER key.
 4 Minus key. 4 2nd Square root key. X,T,theta,n key. Plus key. 4 Right parenthesis key.

 Calculator screen image.
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