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 ?

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- March 20th 2006, 11:09 AMmacca101Exact value of angle

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 ? - March 20th 2006, 04:05 PMtopsquarkQuote:

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.)

-Dan - March 20th 2006, 04:06 PMThePerfectHackerQuote:

Originally Posted by**macca101**

Notice that,

Thus,

That happens, when -memorized.

Notice that,

happens when -memorized.

But, problem ask for

Thus, since

We have that - March 20th 2006, 04:50 PMRich B.
Hi:

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.

Regards,

Rich B - March 21st 2006, 02:43 AMmacca101
Thanks