Find the value V of the Riemann sum V=k=1nf(ck)Δxk\displaystyle {V}={\sum_{{{k}={1}}}^{{n}}}{f{{\left({c}_{{k}}\right)}}}\Delta{x}_{{k}} for the function f(x)=x2+4\displaystyle {f{{\left({x}\right)}}}={x}^{{2}}+{4} using the partition P = { 1, 2, 3, 6 }, where the ck\displaystyle {c}_{{k}} are the left endpoints of the partition. V =