#"let's recall that the average value of a function for an interval"#
#" of (a,b) is given by formula:"#
#k=1/(b-a)int_a^b f(x) d x#
#where;#
#k:"average value"#
#k=1/(6-2)int_2^6(x^2-2x+5)d x#
#k=1/4(|x^3/3-2x^2/2+5x |_2^6)#
#k=1/4(|x^3/3-x^2+5x|_2^6)#
#k=1/4[(6^3/3-6^2+5*6)-(2^3/3-2^2+5*2)]#
#k=1/4[(216/3-36+30)-(8/3-4+10)]#
#k=1/4[(216/3-6)-(8/3+6)]#
#k=1/4[(216-18)/3-(8+18)/3]#
#k=1/4[198/3-26/3]#
#k=1/4[172/3]#
#k=172/12#