hi i need help differentiating these..

Question

1. y = cos(3x^2 + 2x)

2. y = ln(3x^2 + 5)

thank you

Answer 1

use the old chain rule:

y = cos(u)
y' = -sin(u) u' = -sin(3x^2+2x)(6x+2)

y = ln(u)
y' = 1/u u' = 1/(3x^2+5) * 6x = 6x/(3x^2+5)