1 1/x has oscillation â at x = 0, and oscillation 0 at other finite x and at ââ and 2  +â. sin (1/x) (the topologist's sine curve) has oscillation 2 at x = 0, and 0 elsewhere. 3  sin x has oscillation 0 at every finite x, and 2 at ââ and  +â. The sequence 1, â1, 1, â1, 1, â1, ... has oscillation 2.
An herbicide is a chemical used to kill or inhibit the growth of weeds and other unwanted plant pests. There are two kinds of herbicides. Species-specific herbicides are designed to kill a specific kind of plant only, leaving other desirable plants unharmed.hen should you use an herbicide? An herbicide is appropriate any time that you have pest plants or weeds that are competing with desired plants or crops for space, water, light, and nutrients. They are often used in lawn and garden care to achieve a desired aesthetic effect.
Nonselective herbicides kill all vegetation (including turfgrasses) and are used in lawn renovation or on weeds not controlled by selective herbicides. Herbicides can be further divided into preemergence and postemergence categories. Preemergence herbicides are applied prior to germination and emergence of weeds. These are typically used for controlling annual weeds. Postemergence herbicides are used for controlling weeds that have already emerged from the soil. They are either contact or systemic in nature.