# Math Help - help with inverse trigonometric functions

1. ## help with inverse trigonometric functions

I am stuck on these 2 problems and was wondering if someone could work them out for me?

2. what have you tried ?

3. this is a brilliant tool thank you very much! But i do have one problem. For this problem sin&#40;arccos 2&#47;5 - arctan5&#41; - Wolfram|Alpha I need exact form and it gives it ot me in decimal. What can I do?

4. Originally Posted by wonderd
this is a brilliant tool thank you very much! But i do have one problem. For this problem sin&#40;arccos 2&#47;5 - arctan5&#41; - Wolfram|Alpha I need exact form and it gives it ot me in decimal. What can I do?
work it out by hand using the difference identity for sine and some right triangle trig.

5. would someone be willing to work it out for me?

6. What does $\displaystyle \tan{45^{\circ}}$ equal? What is the inverse cosine of that?