# |a| ≥ 0 |
# |a| ≥ 0 |
# |a+b| ≤ |a| + |b| # |a-b| ≥ ||a| - |b|| # it can be expressed: |a| = √ (a2) # For a > 0, |x| ≤ a if and only if -a ≤ x ≤ a |
# |a/b| = |a| / |b| (if b ≠ 0) # |a+b| ≤ |a| + |b| # |a-b| ≥ ||a| - |b|| # |a| = √ (a2) # |a| ≤ b if and only if -b ≤ a ≤ b |
For a complex number z = a + ib, one defines the absolute value or modulus to be |z| = √ (a2 + b2) = √ (z z*). This notion of absolute value shares the properties 1-5 from above. If one interprets z as a point in the plane, then |z| is the distance of z to the origin. |
For a complex number z = a + ib, one defines the absolute value or modulus to be |z| = √ (a2 + b2) = √ (z z*). This notion of absolute value shares the properties 1-6 from above. If one interprets z as a point in the plane, then |z| is the distance of z to the origin. |