Câu 1:
`y=(x^2+2x)/(x-2)`
`toy'=\frac{(x^2+2x)'(x-2)-(x^2+2x)(x-2)'}{(x-2)^2}`
`toy'=\frac{(2x+2)(x-2)-(x^2+2x)}{(x-2)^2}`
`toy'=\frac{2x^2-4x+2x-4-x^2-2x}{(x-2)^2}`
`toy'=\frac{x^2-4x-4}{(x-2)^2}`
Câu 2:
`y=2x^3-x^2+1`
`toy'=(2x^3-x^2+1)'`
`toy'=(2x^3)'-(x^2)'+1'`
`toy'=6x^2-2x`
`toy''=(6x^2-2x)'`
`toy''=(6x^2)'-(2x)'`
`toy''=12x-2`
`toy''(3)=12.3-2=34`
