SOLUTION: Help with this problem?? I keep getting it wrong. Find the exact value of the expression. arctan(tan 5pi/7) And the answer is not pi/7 and I don't know why! What is the answer?

Algebra ->  Trigonometry-basics -> SOLUTION: Help with this problem?? I keep getting it wrong. Find the exact value of the expression. arctan(tan 5pi/7) And the answer is not pi/7 and I don't know why! What is the answer?      Log On


   



Question 811280: Help with this problem?? I keep getting it wrong.
Find the exact value of the expression. arctan(tan 5pi/7) And the answer is not pi/7 and I don't know why! What is the answer?

Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
Find the exact value of the expression.
arctan(tan 5π/7)
Reads:The tan of an angle whose tan=5π/7
So,arctan(tan 5π/7)=5π/7
..
Similarly, arcsin(sin30˚)=30˚
arcsin(sin30˚)=arcsin(1/2)=30˚
or
arccos(cos(x))=x