bjr
(sin u)' = u'cos u
(cos u)' = -u'sin u
il faut connaître les formules
1)
f(x) = cos(3x−5)
u : 3x - 5 ; u' : 3
f'(x) = -3sin(3x - 5)
2)
g(x) = sin(2x)
u : 2x ; u' : 2
g'(x) = 2cos2x
3)
h(x)= cos[(x−3) /3] ; (x-3)/3 = x/3 - 1
u = x/3 - 1 : u' = 1/3
h'(x) = -1/3 sin[(x - 3)/3]
