12.5 	f) plot y^2 = x^2+10x, y^2 = x^2+10x+1y^2 = x^2+10x+2,y^2 = x^2+10x-1 
	i) plot y^2 = x^2+10x+10, y^2=x^2+10x+1, y^2=x^2+10x-8 where y=-10..10
	 

12.13	plot 10^7*e^(2*x), 10^7*e^(-1*x)