定义域 (x-7)/(x^2-49)

解答

定义域

\frac{x - 7}{x ^{2} - 49}

x < - 7 or - 7 < x < 7 or x > 7

间隔符号

(- \infty, - 7) \cup (- 7, 7) \cup (7, \infty)

求解步骤

找到无定义的点（奇点）:

x = 7, x = - 7

函数定义域

x < - 7 or - 7 < x < 7 or x > 7

in t erce pt s \frac{4 x + 7}{8 - 5 x}

mi d p o in t (1 \frac{2}{5}, \frac{6}{5}), (\frac{7}{4}, \frac{1}{4})

d i s t an ce (3, - 4), (5, 1)

p er i o d i c i t y f (x) = - cos (\frac{6 x}{7})

d o main y = \frac{3 x}{x ^{2} - 36}