center: left parenthesis, negative 0.2 , negative 0.5 8 , right parenthesis−0.2,−0.58
宽度：
width: 7.67.6
角度：
angle: 00
高度：
height: 1010
不透明度：
opacity: 11
1
表达式2: arc tangent left parenthesis, StartFraction, "y" Over "x" , EndFraction plus 1 , right parenthesis arc tangent left parenthesis, StartFraction, "y" Over "x" , EndFraction , right parenthesis arc tangent left parenthesis, StartFraction, "y" Over "x" , EndFraction minus 1 , right parenthesis greater than 0arctanyx+1arctanyxarctanyx−1>0
