y = ln(x3) - sin(2x)
dy/dx = (x3)'·(1/x3) - (2x)'cos(2x) <-- Use Chain Rule
dy/dx = 3x2/x3 - 2cos(2x)
dy/dx = 3/x - 2cos(2x)
d2y/dx2 = (3/x)' - (2x)'[-2sin(2x)] <-- Use Chain Rule
d2y/dx2 = -3/x2 - 2[-2sin(2x)]
d2y/dx2 = -3/x2 + 4sin(2x)
Hope this helped!

AJ L.
05/07/23