Calculus
x∈(−∞,∞)x\(\in\)\(\left\)(-\(\infty\),\(\infty\))\(\right\).
y∈(−∞,∞)y\(\in\)\(\left\)(-\(\infty\),\(\infty\))\(\right\).
y∈(−∞,0)∪(0,∞)y\(\in\[\left\)(-\(\infty\),0)\(\right\).\(\cup\]\left\)(0,\(\infty\))\(\right\).
x∈(−∞,0)∪(0,∞)x\(\in\[\left\)(-\(\infty\),0)\(\cup\]\left\)(0,\(\infty\))\(\right\).\(\right\).
x∈(0,∞)x\(\in\)\(\left\)(0,\(\infty\))\(\right\).
y∈(0,∞)y\(\in\)\(\left\)(0,\(\infty\))\(\right\).