\magnification=\magstep2


$$
 a_y \quad = \quad { {d^2 y} \over {d t^2}} \quad = 
$$


$$
  y(t) \quad = \quad  A \cos \left( \omega t + \phi \right) 
$$


$$
  {{ d \thinspace f(x) } \over {dx } } \quad = \quad  A
$$


$$
  {{ d \thinspace f(x) } \over {dx } } \quad = \quad  0
$$

$$
  {{ d \thinspace f(x) } \over {dx } } \quad = \quad  f(x)
$$


$$
  {{ d \thinspace f(x) } \over {dx } } \quad = \quad - f(x)
$$

$$
  {{ d \thinspace f(x) } \over {dx } } \quad = \quad  A f(x)
$$


$$
  {{ d^2 \thinspace f(x) } \over {d x^2 } } \quad = \quad  0
$$

$$
  {{ d^2 \thinspace f(x) } \over {d x^2 } } \quad = \quad  A
$$

$$
  {{ d^2 \thinspace f(x) } \over {d x^2 } } \quad = \quad  A f(x)
$$


$$
  {{ d^2 \thinspace f(x) } \over {d x^2 } } \quad = \quad  -A f(x)
$$



\bye
