exp(x) 	 : returns the exponential of x
	log(x)	 : returns the natural logarithm of x
	max(x,y) : returns the maximum of x and y
	min(x,y) : returns the minimum of x and y
	pow(x,y) : returns x to power y 
	random() : returns random number between 0 and 1 
	round(x) : This method returns x rounded to the closest integer
	sin(x)	 : This method returns the sine of x
	sqrt(x)	 : This method returns the square root of x
	tan(x)	 : This method returns the tangent of x