//return pow(x*log(x),2);//4a
	//return x*sqrt(x-1);//4b
	//return x*x*sqrt(1+3*x*x);//4c
	//return exp(x)*cos(x)*cos(x);//4d
	//return pow(x*sin(x),2);//4e
	//return 1/(2+cos(x))/(3+sin(x));//4f
	//return 3*x*x+x+2;//5a
	//return 2*x*x-x*x+5*x;//5b
	//return 2*x*x*x-3*x;//5c
	//return exp(sqrt(x)+4);//5aT
	//return sqrt(3*x*x-5*x+4);//5bT
	//return x*x*x+2*x/(x*x+1);//5cT