3.5-bo'lim : Trig funksiyalarining hosilalari
3. \(\displaystyle \mathop {\lim }\limits_{x \to \,0} \frac{{\cos \left( {4x} \right) - 1}}{x}\) ni baholang.
Yechim
Biz qilishimiz kerak bo'lgan yagona narsa ushbu bo'limdagi qaydlardagi faktlardan foydalanishimizga imkon berish uchun buni sozlashdir.
\[\mathop {\lim }\limits_{x \to \,0} \frac{{\cos \left( {4x} \right) - 1}}{x} = \mathop {\lim }\limits_{x \to \,0} \frac{{4\left( {\cos \left( {4x} \right) - 1} \right)}}{{4x}} = 4\mathop {\lim }\limits_{x \to \,0} \frac{{\cos \left( {4x} \right) - 1}}{{4x}} = 4\left( 0 \right) = \require{bbox} \bbox[2pt,border:1px solid black]{0}\]