a: \(y'=\left(x^2\right)'+\left(3x\right)'-\left(6x^6\right)'+\left(\dfrac{2x-3}{x-1}\right)'\)

\(=2x+3-6\cdot6x^5+\dfrac{\left(2x-3\right)'\left(x-1\right)-\left(2x-3\right)\left(x-1\right)'}{\left(x-1\right)^2}\)

\(=-36x^5+2x+3+\dfrac{2\left(x-1\right)-2x+3}{\left(x-1\right)^2}\)

\(=-36x^5+2x+3+\dfrac{1}{\left(x-1\right)^2}\)

b: \(\left(\sqrt{2x^2-3x+1}\right)'=\dfrac{\left(2x^2-3x+1\right)'}{2\sqrt{2x^2-3x+1}}\)

\(=\dfrac{4x-3}{2\sqrt{2x^2-3x+1}}\)

\(y'=3\cdot2x-4+\dfrac{4x-3}{2\sqrt{2x^2-3x+1}}\)

\(=6x-4+\dfrac{4x-3}{2\sqrt{2x^2-3x+1}}\)

c: \(\left(\sqrt{4x^2-3x+1}\right)'=\dfrac{\left(4x^2-3x+1\right)'}{2\sqrt{4x^2-3x+1}}\)

\(=\dfrac{8x-3}{2\sqrt{4x^2-3x+1}}\)

\(y'=\left(\sqrt{4x^2-3x+1}\right)'-4'=\dfrac{8x-3}{2\sqrt{4x^2-3x+1}}\)

a. \(y'=\dfrac{-1}{\left(x-1\right)}\)

b. \(y'=\dfrac{5}{\left(1-3x\right)^2}\)

c. \(y=\dfrac{\left(x+1\right)^2+1}{x+1}=x+1+\dfrac{1}{x+1}\Rightarrow y'=1-\dfrac{1}{\left(x+1\right)^2}=\dfrac{x^2+2x}{\left(x+1\right)^2}\)

d. \(y'=\dfrac{4x\left(x^2-2x-3\right)-2x^2\left(2x-2\right)}{\left(x^2-2x-3\right)^2}=\dfrac{-4x^2-12x}{\left(x^2-2x-3\right)^2}\)

e. \(y'=1+\dfrac{2}{\left(x-1\right)^2}=\dfrac{x^2-2x+3}{\left(x-1\right)^2}\)

g. \(y'=\dfrac{\left(4x-4\right)\left(2x+1\right)-2\left(2x^2-4x+5\right)}{\left(2x+1\right)^2}=\dfrac{4x^2+4x-14}{\left(2x+1\right)^2}\)

2.

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

b. \(y'=5\left(1-2x^2\right)^4.\left(1-2x^2\right)'=-20x\left(1-2x^2\right)^4\)

c. \(y'=3\left(\dfrac{2x+1}{x-1}\right)^2.\left(\dfrac{2x+1}{x-1}\right)'=3\left(\dfrac{2x+1}{x-1}\right)^2.\left(\dfrac{-3}{\left(x-1\right)^2}\right)=\dfrac{-9\left(2x+1\right)^2}{\left(x-1\right)^4}\)

d. \(y'=\dfrac{2\left(x+1\right)\left(x-1\right)^3-3\left(x-1\right)^2\left(x+1\right)^2}{\left(x-1\right)^6}=\dfrac{-x^2-6x-5}{\left(x-1\right)^4}\)

e. \(y'=-\dfrac{\left[\left(x^2-2x+5\right)^2\right]'}{\left(x^2-2x+5\right)^4}=-\dfrac{2\left(x^2-2x+5\right)\left(2x-2\right)}{\left(x^2-2x+5\right)^4}=-\dfrac{4\left(x-1\right)}{\left(x^2-2x+5\right)^3}\)

f. \(y'=4\left(3-2x^2\right)^3.\left(3-2x^2\right)'=-16x\left(3-2x^2\right)^3\)

`a)TXĐ:R\\{1;1/3}`

`y'=[-4(6x-4)]/[(3x^2-4x+1)^5]`

`b)TXĐ:R`

`y'=2x. 3^[x^2-1] ln 3-e^[-x+1]`

`c)TXĐ: (4;+oo)`

`y'=[2x-4]/[x^2-4x]+2/[(2x-1).ln 3]`

`d)TXĐ:(0;+oo)`

`y'=ln x+2/[(x+1)^2].2^[[x-1]/[x+1]].ln 2`

`e)TXĐ:(-oo;-1)uu(1;+oo)`

`y'=-7x^[-8]-[2x]/[x^2-1]`

Lời giải:
a.

$y'=-4(3x^2-4x+1)^{-5}(3x^2-4x+1)'$

$=-4(3x^2-4x+1)^{-5}(6x-4)$

$=-8(3x-2)(3x^2-4x+1)^{-5}$

b.

$y'=(3^{x^2-1})'+(e^{-x+1})'$

$=(x^2-1)'3^{x^2-1}\ln 3 + (-x+1)'e^{-x+1}$

$=2x.3^{x^2-1}.\ln 3 -e^{-x+1}$

c.

$y'=\frac{(x^2-4x)'}{x^2-4x}+\frac{(2x-1)'}{(2x-1)\ln 3}$

$=\frac{2x-4}{x^2-4x}+\frac{2}{(2x-1)\ln 3}$

d.

\(y'=(x\ln x)'+(2^{\frac{x-1}{x+1}})'=x(\ln x)'+x'\ln x+(\frac{x-1}{x+1})'.2^{\frac{x-1}{x+1}}\ln 2\)

\(=x.\frac{1}{x}+\ln x+\frac{2}{(x+1)^2}.2^{\frac{x-1}{x+1}}\ln 2\\ =1+\ln x+\frac{2^{\frac{2x}{x+1}}\ln 2}{(x+1)^2}\)

e.

\(y'=-7x^{-8}-\frac{(x^2-1)'}{x^2-1}=-7x^{-8}-\frac{2x}{x^2-1}\)

tham khảo:

a)y′=2\(^{3x-x^2}\).ln2.(3−2x)

b) y′\(\dfrac{4}{ln3}\).\(\dfrac{1}{4x+1}\).4=\(\dfrac{4}{\left(4x+1\right)ln3}\)

Chọn D.

Trước hết ta xét: \(g\left(x\right)=\dfrac{1}{x+a}=\left(x+a\right)^{-1}\) với a là hằng số bất kì

\(g'\left(x\right)=-1.\left(x+a\right)^{-2}=\left(-1\right)^1.1!.\left(x+a\right)^{-\left(1+1\right)}\) 

\(g''\left(x\right)=-1.\left(-2\right).\left(x+a\right)^{-3}=\left(-1\right)^2.2!.\left(x+a\right)^{-\left(2+1\right)}\)

Từ đó ta dễ dàng tổng quát được:

 \(g^{\left(n\right)}\left(x\right)=\left(-1\right)^n.n!.\left(x+a\right)^{-\left(n+1\right)}=\dfrac{\left(-1\right)^n.n!}{\left(x+a\right)^{n+1}}\)

Xét: \(f\left(x\right)=\dfrac{x^2+1}{x\left(x-2\right)\left(x+2\right)}=-\dfrac{1}{4}.\left(\dfrac{1}{x}\right)+\dfrac{5}{8}\left(\dfrac{1}{x+2}\right)+\dfrac{5}{8}\left(\dfrac{1}{x-2}\right)\)

Áp dụng công thức trên ta được:

\(f^{\left(30\right)}\left(1\right)=\dfrac{1}{4}.\dfrac{\left(-1\right)^{30}.30!}{1^{31}}+\dfrac{5}{8}.\dfrac{\left(-1\right)^{30}.30!}{\left(1+2\right)^{31}}+\dfrac{5}{8}.\dfrac{\left(-1\right)^{30}.30!}{\left(1-2\right)^{31}}\)

Bạn tự rút gọn kết quả nhé

\(f\left(x\right)=\dfrac{x^2+1}{x^3}-4x\) hay \(f\left(x\right)=\dfrac{x^2+1}{x^3-4x}\) bạn?

\(a,y'=\left[\left(2x-3\right)^{10}\right]'\\ =10\left(2x-3\right)^9\left(2x-3\right)'\\ =20\left(2x-3\right)^9\\ b,y'=\left(\sqrt{1-x^2}\right)'\\ =\dfrac{\left(1-x^2\right)'}{2\sqrt{1-x^2}}\\ =-\dfrac{2x}{2\sqrt{1-x^2}}\\ =-\dfrac{x}{\sqrt{1-x^2}}\)

y ' =    ( ​ 4 x + 1 ) ' . x 2 + 2 − ( 4 x + 1 ) . ( x 2 + ​ 2 ) ' x 2 + 2 = 4. x 2 + 2 − ( 4 x + 1 ) ​ . x x 2 + 2 x 2 + ​ 2 =    4 ( x 2 + ​ 2 ) − ( ​ 4 x + 1 ) . x ( x 2 + ​ 2 ) . x 2 + ​ 2 =   − x + ​ 8 ( x 2 + ​ 2 ) . x 2 + ​ 2

ĐÁP ÁN D