Returns one of two values, depending on a test condition.
IF(test; value1; value2) where:
If value2 is omitted it is assumed to be FALSE; if value1 is also omitted it is assumed to be TRUE.
IF(A1>5; 100; "too small")
IF(1>2; "nonsense")
IF(2>1)
IF(1=2; 1/0; SQRT(4))