The above is a formal way of going about it, but for quick mental calculations, remembering that #i^4=1# allows you to "pull out" the greatest multiple of 4 possible from the exponent.
This leaves you with an exponent of 0, 1, 2, or 3 (any greater and there is another multiple of 4 to remove).
Then it is easy to work out that #i^0 = 1# , #i^1 = i# , #i^2 = -1# , and #i^3 = -i# .
Enter equation to graph, e.g. y=3x^2-1
Sports, which are dangerous for us, shouldn't take part in our life. Some people aren't bothered by it because an extreme sport is the most important thing in their lives, while others are angry about it because they think that people are menaced by extreme and can break up with life.
I think that the extreme sports shouldn't be banned. Because they always allow us to be in good physical shape and have a good health. In addition, they allow us to feel something exciting and interesting. Therefore, I consider that it's an integral part of our life.
But more people also think that the extreme sports should be banned. Firstly, if someone doesn't have basic skills, he can injure and, moreover, can die. The most of them don't find anything attractive in it.
I don't agree with the opposing opinion because if you have a special equipment and proper training, you can't injure.
All in all, I think that the extreme sports play an important part in our life. Although, they're dangerous, they inspire us to explore something which is new, unknown and interesting. It allows us to be active and debonuire people.