avoid evaluating calls to function help (because it print the content of the man page in the log)

session_1/session_1.Rmd

@@ -460,13 +460,13 @@ function (x, base = exp(1))
 
 To know more about the `log` function we can read its manual.
 
-```{r VandAstep8, include=TRUE}
+```{r VandAstep8, include=TRUE, eval=FALSE}
 help(log)
 ```
 
 or
 
-```{r VandAstep9, include=TRUE}
+```{r VandAstep9, include=TRUE, eval=FALSE}
 ?log
 ```
 
@@ -805,7 +805,7 @@ Check the documentation of this command
 
 <details><summary>Solution</summary>
 <p>
-```{r VandAstep16, include=TRUE}
+```{r VandAstep16, include=TRUE, eval=FALSE}
 ?rm
 ```
 </p>

session_2/session_2.Rmd

@@ -155,7 +155,7 @@ It contains only models which had a new release every year between 1999 and 2008
 
 You can use the `?` command to know more about this dataset.
 
-```{r mpg_inspect, include=TRUE}
+```{r mpg_inspect, include=TRUE, eval=FALSE}
 ?mpg
 ```
 

session_6/session_6.Rmd

@@ -52,7 +52,7 @@ Use the help to know more about `table1` dataset
 
 <details><summary>Solution</summary>
 
-```{r}
+```{r, eval=FALSE}
 ?table1
 ```