Where I and II are my two solutions.
The answer given in my book are:
In this post I use a plus and a minus following eachother (like this: +-) to indicate that the following term can be either negative or positive.
To show (for my self maninly) that what I do is indeed right.
I included it here just because I thought it was possible that it was somewhere there I did something wrong.
If someone would say, hey there is your fault!
Then I colud more easily trace it if I did it like I did it rather than how you did it, don't you think?
Conclusion: I do it because I am a little rusty in trigonometry.
Yes, the inverse cosine function.Originally Posted by Quick
how do you remove the square.
You use the inverse function which removes it.
However, over here that value is one of the trigonometric values that you need to have memorized.
So when it is negative, it is either in the 2nd or 3rd quadrant so,