Page 58 - Calc for the Clueless
P. 58
Possible inflection points: y" = 0. Using the quadratic formula and then substituting these values into the
original, we get approximately (2.34,4.86) and (-0.34,9.23). These are both inflection points. Test for cusps:
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+
|f'(0)| is infinite, f(0) = 0. f'(0 ) is negative and f'(0 ) is positive. Cusp points down. Left-end and right-end
2/3
substitution: f(-1) = 25 (-1,25), f(5) = 5 . The point is approximately (5,2.92).
Whew!!!! Let us sketch:
Other Aids
Symmetry:
1. f(x) = f(-x). Symmetrical about the y axis.
2. f(x) = -f(-x). Symmetrical about the origin.
3. g(y) = g(-y). Symmetrical about the x axis. This is only found in graphing curves that are not functions of x.
Example 31—
y axis symmetry
Example 32—
Symmetric origin