Asosiy tarkibga o'tish

2.3-bo'lim : Bir tomonlama chegaralar

4. Quyidagi shartlarning har birini qanoatlantiradigan funksiya grafigini chizing.

\[\begin{array}{ccl}\mathop {\lim }\limits_{x \to {3^{\, - }}} f\left( x \right) = 0 & \hspace{0.5in}\mathop {\lim }\limits_{x \to {3^{\, + }}} f\left( x \right) = 4 & \hspace{0.5in}f\left( 3 \right){\mbox{ does not exist}}\\ \mathop {\lim }\limits_{x \to - 1} f\left( x \right) = - 3 & \hspace{0.5in} f\left( { - 1} \right) = 2 & \end{array}\]
Yechim

Bu erda javob berish uchun tom ma'noda cheksiz ko'p mumkin bo'lgan grafiklar mavjud. Biroq, ularning barchasi quyidagi ikkita mezon to'plamiga ega bo'lishi kerak.

Birinchidan, \(x = 3\) da grafikda yopiq nuqta bo‘lishi mumkin emas (bu funksiya bu yerda mavjud emasligidan dalolat beradi), grafik \(x = 3\) ga chapdan yaqinlashganda (chap chegara bilan ko‘rsatilgandek) 0 qiymatiga yaqinlashishi kerak va \(x = 3\) chegarasidan o‘ng tomondan ko‘rsatilgan holda 4 ga yaqinlashishi kerak.

Keyinchalik, grafik \(\left( { - 1,2} \right)\) nuqtasida yopiq nuqtaga ega bo'lishi kerak va grafik \(x = - 1\) ga har ikki tomondan yaqinlashganda -3 qiymatiga yaqinlashishi kerak (bu nuqtada umumiy chegara qiymati -3 ga teng ekanligidan dalolat beradi).

Mana shu shartlarga javob beradigan bitta mumkin bo'lgan grafikning eskizi.

One possible graph of a function satisfying the given conditions, shown for \(-2 \le x \le 5\).  The first piece starts at about (-2,-1), falls through an open dot at (-1,-3) to a minimum of about -4 near \(x = 0.3\) and then rises to an open dot at (3,0).  There is a closed dot at (-1,2) above the open dot at \(x = -1\).  The second piece starts at an open dot at (3,4), rises to a peak of a little over 5 near \(x = 3.7\) and then falls to (5,0).