Answer:
[tex]-\sqrt{2} -1[/tex]
Step-by-step explanation:
[tex]tan(\alpha/2)=\frac{1-cos\alpha }{sin\alpha } \\tan(112.5)=tan(225/2)=\frac{1-cos225 }{sin225 }=\frac{1+cos45}{-sin45}=\frac{1+\frac{1}{\sqrt{2} } }{\frac{-1}{\sqrt{2} } }= -\sqrt{2} -1[/tex]
