Q: Volume of revolution of $y=\sqrt {x+2},y=x,y=0$ about $x$-axis using the shell method.My Approach: I know how to use shell method. For shell method height and radius are the main thing, because $V=2\pi\int R(y)H(y)dy$ That's why I found height $H(y)=y-(y^2-2).$ But I cannot write $R(y)$, because for $x\in[-2,0]$ the lower curve is $y=0$ and for $x\in[0,2]$ the lower curve is $y=x$. Then how could i find the volume using shell method. Any hints or solution will be appreciated.Thanks in advance.