Réponse :
Explications étape par étape :
■ tan(x - π/2) = -1 donne
x - π/2 = -π/4 OU x - π/2 = 3π/4
x = π/4 OU x = 5π/4
Solution = { π/4 + kπ } .
■ cos(3x) = cos(2x - π/3)
on cherche d' abord sur [ 0 ; 2π ] :
donne x = π/15 ou x = 7π/15 ou x = 13π/15 ou x = 19π/15 ou x = 25π/15
Solution = { π/15 + 2kπ/5 } .
