there are 21 people at Thanksgiving dinner , if each person hugs everyone else only once , how many hugs take place at the party
2 answers:
You might be interested in
I think you might be referring to the definite integral,
Recall the definition of absolute value:
Then if
, and
is
. So spliting up the integral at <em>x</em> = 1, we have
The rest is simple: