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

Задание

Заполните таблицу значений функции \(\displaystyle y=-3|x-2|-1{\small .}\)

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

 

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


Постройте график по полученным точкам:
 

Решение

Заполним таблицу значений функции \(\displaystyle y=-3|x-2|-1{\small :}\)

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

 

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


Вычислим значения:

\(\displaystyle x\)\(\displaystyle \small -1\)\(\displaystyle \small 0\)\(\displaystyle \small 1\)
\(\displaystyle y=-3|x-2|-1\)\(\displaystyle \small -10\)\(\displaystyle \small -7\)\(\displaystyle \small -4\)

 

\(\displaystyle x\)\(\displaystyle \small 2\)\(\displaystyle \small 3\)\(\displaystyle \small 4\)\(\displaystyle \small 5\)
\(\displaystyle y=-3|x-2|-1\)\(\displaystyle \small -1\)\(\displaystyle \small -4\)\(\displaystyle \small -7\)\(\displaystyle \small -10\)


Построим точки на плоскости и соединим их линией:


Получили график функции \(\displaystyle y=-3|x-2|-1\) на отрезке \(\displaystyle [-1;5]{\small .}\)