HP 48gII Graphing, 50g Graphing COS, COV, COSH

COS

Type:	Analytic Function
Description:	Cosine Analytic Function: Returns the cosine of the argument.
	For real arguments, the current angle mode determines the number’s interpretation as an angle,
	unless the angular units are specified.
	For complex arguments, cos(x + iy) = cosx coshy – i sinx sinhy.
	If the argument for COS is a unit object, then the specified angular unit overrides the angle mode
	to determine the result. Integration and differentiation, on the other hand, always observe the
	angle mode. Therefore, to correctly integrate or differentiate expressions containing COS with a
	unit object, the angle mode must be set to Radians (since this is a “neutral” mode).
Access:	T
Flags:	Numerical Results (–3), Angle Mode (–17, –18)
Input/Output:
				Level 1/Argument 1							Level 1/Item 1
					z				→		cos z
					'symb'				→		'COS(symb)'
				x_unitangular					→		cos (x_unitangular)
	ACOS, SIN,
See also:			TAN
COSH	Analytic Function
Type:
Description:	Hyperbolic Cosine Analytic Function: Returns the hyperbolic cosine of the argument.
	For complex arguments, cosh(x + iy) = coshx cosy + i sinhx siny.
Access:	…ÑHYPERBOLIC COSH				(Ñis the right-shift of the 8key).
	!´HYPERBOLIC COSH				( ´is the left-shift of the Pkey).
Flags:	Numerical Results (–3)
Input/Output:
				Level 1/Argument 1							Level 1/Item 1
					z				→		cosh z
					'symb'				→		'COSH(symb)'
See also:	ACOSH, SINH, TANH
COV	Command
Type:
Description:	Covariance Command: Returns the sample covariance of the independent and dependent data
	columns in the current statistics matrix (reserved variable ΣDAT).
	The columns are specified by the first two elements in reserved variable ΣPAR, set by XCOL and
	YCOL respectively. If ΣPAR does not exist, COV creates it and sets the elements to their default
	values (1 and 2).
	The covariance is calculated with the following formula:
					1	n
					-----------	∑ (xin1	– xn1 )(xin2 – xn2 )
					n – 1i = 1
	where xin1 is the ith coordinate value in column n1, xin2 is the ith coordinate value in the column
	n2,	is thexn1mean of the data in column n1,					is the			of the data in column n2, and n is the
									nmean2
								x
	number of data points.
Access:	…µCOV

3-46 Full Command and Function Reference