User:LlewS/drafts/Funct. Anal.

1. make I italic font 2. get "Find ..." indented properly 3. get norm symbol instead of two veritical bars

3. Let $$H = R^2,$$ with $$Y = \{(x,0) | x \in R\} \quad 0 < \theta <\pi /2.$$ Find the formula for the idempotent $$I_{\theta} \quad (i.e., I_{\theta}^2 = I_{\theta})$$ with range $$(I_{\theta}) = Y $$ and kernel $$(I_{\theta}) = Z $$ and show that $$||I_{\theta}|| = \frac{1}{\sin(\theta)}.$$