
<=> cosx = +1/2 or cosx = -1/2;
cosx = +1/2 => x = +π/3 + 2kπ, where k is an integer or x = -π/3 + 2kπ, where k is an integer;
cosx = -1/2 => x = +2π/3 + 2kπ, where k is an integer or x = -2π/3 + 2kπ, where k is an integer;
First the person with a flashlight and one of his friends cross the bridge. After that same person with a flashlight comes back and leads another friend to the other side. Finally he comes back again and leads the last of them.
Number of times that he will have to cross the bridge is 5 ( five ).
The second one is a perfect square trinomial
X^2+16x+64
4 because that is what's multiplied throughout
Okie so I can see you tomorrow and I’ll be right there on time to meet