Asosiy tarkibga o'tish

4.11-bo'lim : Chiziqli taxminlar

2. \(t = - 3\) da \(h\left( t \right) = {t^4} - 6{t^3} + 3t - 7\) ga chiziqli yaqinlashishni toping.

Yechim

Bizga birinchi navbatda hosila va bir nechta funktsiyani baholash kerak bo'ladi.

\[h'\left( t \right) = 4{t^3} - 18{t^2} + 3\hspace{0.5in}h\left( { - 3} \right) = 227\hspace{0.5in}h'\left( { - 3} \right) = - 267\]
2-qadam

Haqiqatan ham bu nuqtada chiziqli yaqinlashishni yozishdan boshqa ko'p narsa qilish kerak emas.

\[\require{bbox} \bbox[2pt,border:1px solid black]{{L\left( t \right) = 227 - 267\left( {t + 3} \right) = - 267t - 574}}\]

Bu so'ralmagan bo'lsa-da, bu erda funktsiyaning qisqacha eskizi va chiziqli yaqinlashish.

The graph of \(h\left( t \right) = {t^4} - 6{t^3} + 3t - 7\) together with its linear approximation \(L\left( t \right) = - 267t - 574\).  Both fall steeply from the upper left and they touch at \(t = - 3\).  Away from that point the curve stays above the line, pulling away from it sharply on both sides.