f′(x)= 1/[(x^4(x^3+5x^2+3x+ 15)^8]*[4(x^3)*(x^3+5x^2+3x+ 15)^8+(x^4)*8(x^3+5x^2+3x+ 15)^7*(3x^2+ 10x+3)

=4(x^3)*(x^3+5x^2+3x+ 15)^7*[(x^3+5x^2+3x+ 15)+2*(3x^2+ 10x+3)]/[(x^4(x^3+5x^2+3x+ 15)^8]

=4*(x^3+ 1 1x^2+23x+2 1)*(x^3+5x^2+3x+ 15)^7/[x*(x^3+5x^2+3x+ 15)^8]

2:f(x)=6x^3+2x- 1=7

(x- 1) (3x 2+3x+4) = 0, and x= 1 is obtained.

g(7)= 1，

As an implicit function equation, 6x 3+2x- 1 = y, and when x= 1, y=7.

Derive x on both sides of the equation and get: 18x 2 * x'+2x' = 1.

x′= 1/( 18x^2+2)= 1/20，(x= 1)

So g'(7)= 1/20.