2 added 29 characters in body edited Sep 15 '13 at 10:08 Juho 16.8k55 gold badges4343 silver badges9393 bronze badges for n<=6For $$n \leq 6$$, $$1/2 - 3/n \le0$$$$1/2 - 3/n \le0,$$ so if you are taking integer value of n$$n$$, put n = 7$$n = 7$$ as it gives 1/14 this$$1/14$$. This is how he arrived in the conclusion iei.e., for $$n \geq 7$$, $$n\ge7$$ $$1/2 - 3/n \ge1/14$$$$1/2 - 3/n \ge1/14,$$ because n$$n$$ is in the denominator it will only decrease the value of -ve term, so overall value will increase with n $$n$$,which which is the constant c1$$c_1$$. for n<=6 $$1/2 - 3/n \le0$$ so if you are taking integer value of n, put n = 7 it gives 1/14 this is how he arrived in the conclusion ie, for $$n\ge7$$ $$1/2 - 3/n \ge1/14$$ because n is in denominator it will only decrease the value of -ve term so overall value will increase with n ,which is the constant c1. For $$n \leq 6$$, $$1/2 - 3/n \le0,$$ so if you are taking integer value of $$n$$, put $$n = 7$$ as it gives $$1/14$$. This is how he arrived in the conclusion i.e., for $$n \geq 7$$, $$1/2 - 3/n \ge1/14,$$ because $$n$$ is in the denominator it will only decrease the value of -ve term, so overall value will increase with $$n$$, which is the constant $$c_1$$. 1 answered Sep 15 '13 at 9:04 p.j 25511 silver badge66 bronze badges for n<=6 $$1/2 - 3/n \le0$$ so if you are taking integer value of n, put n = 7 it gives 1/14 this is how he arrived in the conclusion ie, for $$n\ge7$$ $$1/2 - 3/n \ge1/14$$ because n is in denominator it will only decrease the value of -ve term so overall value will increase with n ,which is the constant c1.