[vandame]

how do u solve this problems
sin x + 2sinxcosx
tanx(tanx + 1)= 0

[kyop]

how do u solve this problems
sin x + 2sinxcosx
tanx(tanx + 1)= 0

You would utilize the trigonometric identities. My question is, are those two separate problems or just one? Please clarify the question and I can help better.

[s_cianci]

Yes, the first one sin x + 2sin x cos x appears to be incomplete. As for the second one, set each factor = 0:

tan x = 0 tan x + 1 = 0

tan x = -1

On the domain [0 , 2pi):

x = 0 , pi (generated by tan x = 0)
x = 3pi/4 , 7pi/4 (generated by tan x = -1)