Question

Choose the statement which is equivalent to sin(x)+cos(x)=0
Tan(x)=1
Tan(x)=-1
Cot(x)=1
Tan(x)=0

Answer 1

$\sin(x) + \cos(x) = 0 \\ \Leftrightarrow \sin(x) = - \cos(x) \\ \Leftrightarrow \frac{ \sin(x) }{ \cos(x) } = - 1\Leftrightarrow \tan(x) = - 1$