What is the acceleration vector for the given position and velocity vectors?

[cue928]

For the following position vector I am being asked to find the acceleration at t=1:
r(t) = (t^5)i + 8ln(1/(6+t))j + (9/t)k

I had the following for the velocity vector:
v(t) = (5t^4)i + (-8/(6+t))j - (9/t^2)k

For the acceleration vector I had:
a(t) = (20t^3)i + (8/(t+6)^2)j + (18/t^3)k

a(1) = 20 i + (8/49)j + 18 k

According to the book, a(1) = 20i + 8j + 18k is the correct answer, does anyone see where I went wrong or is it a mistake in the book?

 

[vela]

The book's wrong.