Bài 2 trang 61 sgk giải tích 12


Nội dung bài giảng

Bài 2. Tìm các đạo hàm của các hàm số:

a) \(y= \left ( 2x^{2} -x+1\right )^{\frac{1}{3}}\);

b) \(y= \left ( 4-x-x^{2}\right )^{\frac{1}{4}}\);

c) \(y= \left ( 3x+1\right )^{\frac{\pi }{2}}\);

d) \(y= \left ( 5-x\right )^{\sqrt{3}}\).

Giải

a)  \(y^{'}=\frac{1}{3}\left ( 2x^{2} -x+1\right )^{'}\left (2x^{2}-x+1 \right )^{\frac{1}{3}-1}\)=  \(\frac{\left ( 4x-1\right )\left ( 2x^{2}-x+1 \right )^{\frac{-2}{3}}}{3}\).

b) \(y^{'}=\frac{1}{4}\left ( 4-x-x^{2} \right )^{'}\left ( 4-x-x^{2} \right )^{\frac{1}{4}-1}\)= \(\frac{1}{4}\left ( -2x-1 \right )\left ( 4-x-x^{2} \right )^{\frac{-3}{4}}\).

c) \(y^{'}\)= \(\frac{\pi }{2}\left ( 3x+1 \right )^{'}\left ( 3x+1 \right )^{\frac{\pi }{2}-1}\)= \(\frac{3\pi }{2}\left ( 3x+1 \right )^{\frac{\pi }{2}-1}\).

d) \(y^{'}\)= \(\sqrt{3}\left ( 5-x \right )^{'}\left ( 5-x \right )^{\sqrt{3}-1}\)= \(-\sqrt{3}\left ( 5-x \right )^{\sqrt{3}-1}\).