4.4	d) plot pi/2 + arcsin x, arcsin x
	e) plot e^(-2x) , e^(-x), e^x
	l) plot tan (x-2\pi), tan x

4.6	A) plot tan x
	E) plot arcsin x
	G) plot e^(-x)
	H) plot 1/sqrt(x)
	K) plot x^4
	O) plot 1/x^2

4.9	b) plot sqrt(x^2-4)
	d) plot 1/log_10(1-x)+sqrt(x+2), sqrt(3), 1/log_10(3) where x from -2 to 1
	g) plot arccos(2/(1+x))
	   plot 2/(1+x)
	   plot arccos x

4.10	b) plot x(5^(2x)-5^(-2x))
	c) plot arcsin x/arctan x
	e) plot sin x - cos x

4.11	b) plot cos(3x)
	c) plot x^2

4.13	b) plot -sqrt(x)
	d) plot 2-10^(x-1) , 1+log|x-2| 
	f) plot 1+arccos(1-x) plot 1-cos(x-1) where x from 1 to pi +1

4.14	a) Plot[y= x-5+ln(x-5)]
	   ParametricPlot[{t+5},{t+ln t}]

4.15	b) Plot[x = ln(y-sin x)], Plot{y=e^x+sin x}

4.16	b) plot 2^x
	d) plot x^2
	f) plot sin x