Question

Question #74173

Answer 1

Given that `\Delta r=(12-6)/x=6/x` and `r_i=6+i*Delta r`:
`lim_(x\to oo)(sum_(i=1)^x6r_i*sin(r_i)\Deltar)=int_6^(12)r*sin(r)dr`

(It's kind of weird to use `x` the way it is used in this problem; mostly you see these problems with `n` replacing the `x`.)