Find the exact value of the angle in radians and justify your answer.
I'm stuck on this one why can't I just use the arctan function on my calculator? I know I can't that would be too simple. Can any one give me a clue ?
Well, cos = 1/sec so we have that , which leads us to which implies that . Where in do we find such an angle? is the only one I can think of.Originally Posted by macca101
The reason that just taking the inverse tangent won't work is that you will get a list of possibles and the answer is buried in there. However, you could do the inverse tangent and inverse secant and compare the two lists...(rather like what I did with the sine and cosine values.)
There are some anlges that you need to have remorzied to be able to answer this question.Originally Posted by macca101
That happens, when -memorized.
happens when -memorized.
But, problem ask for
We have that
In evaluating arctan [-sqrt(3)], your calculator will provide a decimal approximation to the tune of -1.0471975511 ± a few decimal places. But the problem is specific in calling for an EXACT value of theta which, as it happens, is irrational and therefore with infinitely many non-repeating digits to the right of the decimal point. And this is why you are well advised by PHckr, to commit exact trigonometric values of certain key angles to memory.