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Теория: 15 Построение графика функции, содержащей модуль, по точкам

Задание

Заполните таблицу значений функции \(\displaystyle y=|x+3|{\small .}\)

\(\displaystyle \small x\)\(\displaystyle \small -8\)\(\displaystyle \small -7\)\(\displaystyle \small -6\)\(\displaystyle \small -5\)\(\displaystyle \small -4\)
\(\displaystyle \small y=|x+3|\)

 

\(\displaystyle \small x\)\(\displaystyle \small -3\)\(\displaystyle \small -2\)\(\displaystyle \small -1\)\(\displaystyle \small 0\)\(\displaystyle \small 1\)\(\displaystyle \small 2\)
\(\displaystyle \small y=|x+3|\)


Постройте график по полученным точкам:
 

Решение

Заполним таблицу значений функции \(\displaystyle y=|x+3|{\small :}\)

\(\displaystyle x\)\(\displaystyle \small -8\)\(\displaystyle \small -7\)\(\displaystyle \small -6\)\(\displaystyle \small -5\)\(\displaystyle \small -4\)
\(\displaystyle y=|x+3|\)\(\displaystyle \small |-8+3|\)\(\displaystyle \small |-7+3|\)\(\displaystyle \small |-6+3|\)\(\displaystyle \small |-5+3|\)\(\displaystyle \small |-4+3|\)

 

\(\displaystyle x\)\(\displaystyle \small -3\)\(\displaystyle \small -2\)\(\displaystyle \small -1\)\(\displaystyle \small 0\)\(\displaystyle \small 1\)\(\displaystyle \small 2\)
\(\displaystyle y=|x+3|\)\(\displaystyle \small |-3+3|\)\(\displaystyle \small |-2+3|\)\(\displaystyle \small |-1+3|\)\(\displaystyle \small |0+3|\)\(\displaystyle \small |1+3|\)\(\displaystyle \small |2+3|\)


Вычислим значения:

\(\displaystyle x\)\(\displaystyle \small -8\)\(\displaystyle \small -7\)\(\displaystyle \small -6\)\(\displaystyle \small -5\)\(\displaystyle \small -4\)
\(\displaystyle y=|x+3|\)\(\displaystyle \small 5\)\(\displaystyle \small 4\)\(\displaystyle \small 3\)\(\displaystyle \small 2\)\(\displaystyle \small 1\)

 

\(\displaystyle x\)\(\displaystyle \small -3\)\(\displaystyle \small -2\)\(\displaystyle \small -1\)\(\displaystyle \small 0\)\(\displaystyle \small 1\)\(\displaystyle \small 2\)
\(\displaystyle y=|x+3|\)\(\displaystyle \small 0\)\(\displaystyle \small 1\)\(\displaystyle \small 2\)\(\displaystyle \small 3\)\(\displaystyle \small 4\)\(\displaystyle \small 5\)


Построим точки на плоскости и соединим их линией:


Получили график функции \(\displaystyle y=|x+3|\) на отрезке \(\displaystyle [-8;2]{\small .}\)