The angle measure of DBC is 45
Answer:
I believe the correct answer is B.
From my notes I’ve the derivative of arctan(x)= 1/(1+x^2)
= -9(x – 4) – 6x
Multiply -9 by everything in parentheses first
= (-9*x) + (-9*-4) - 6x
= -9x + (36) - 6x
Combine like terms
= (-9x-6x) + 36
= -15x + 36
The middle choice is the answer:
-15x + 36
Hope this helps! :)