Question

根号下是x平方-7x的负一次方

Answer 1

1、

[(3e^x-2x^3) /(3e^x+2x^3)]'

=[1- 4x^3/(3e^x+2x^3) ]'

=[(-4x^3)'*(3e^x+2x^3)+4x^3*(3e^x+2x^3)' ] /(3e^x+2x^3)²

=[(-12x²)*(3e^x+2x^3)+4x^3*(3e^x+6x²)] /(3e^x+2x^3)²

=(-36x² *e^x+12x^3 *e^x) /(3e^x+2x^3)²

2、

sin[√(x²-7/x)] '

=cos[√(x²-7/x)] * [√(x²-7/x)]'

=cos[√(x²-7/x)] * (x²-7/x)'/ 2√(x²-7/x)

=cos[√(x²-7/x)] * (2x+7/x²)/ 2√(x²-7/x)

3、

[5cos(4x^3-1)*tanx]'

=[5cos(4x^3-1)]' *tanx + 5cos(4x^3-1)*(tanx)'

= -5sin(4x^3-1)* 12x² *tanx + 5cos(4x^3-1)* /cos²x

= -60x² *sin(4x^3-1)* tanx + 5cos(4x^3-1)* /cos²x