show that the given equation is not an identity tan x = 1

Question

im lost help

Answer 1

To be an identity, it would have to be true for all x.  It is sufficient to show that it is false for at least one x.

 

Let x = 0

 

tan(0) = 0 ≠ 1

 

Therefore,

 

tan(x) = 1 is not an identity.  However, there are values of x that do satisfy the equation, so tan(x) = 1 has solutions, but it is not an identity.