## anonymous 4 years ago May someone show me how to solve this problem? Find the exact value of the trigonometric function. Do not use a calculator. 5) sin 5π/4

1. anonymous

Please :( can someone help me, its pre-calc

2. Hero

Hint: Let $$\pi = 180$$

3. anonymous

-_- omg... is it -sqrt2/sqrt2?

4. Hero

Yup, you got it

5. anonymous

lol i feel so dumb now lol XD thanks!

6. Hero

Why? The technique of letting pi = 180 is not very popular.

7. Hero

In fact, your teacher may not approve of the steps

8. anonymous

oh because in my class we had to draw out a circle with different measuements and memorize it, and i completely forgot that i was supposed to use the circle to solve it

9. Hero

I mean I would solve it algebraically as you have using the substitution of pi with 180, but the thing is, now that you know what the exact value is, you can still do it the way your teacher wants.

10. Hero

letting pi = 180 saves you from having to memorize the circle.

11. Hero

There's another technique that amistre 64 knows that's a huge shortcut for memorizing the unit circle that I know you would like. Ask him about it.

12. anonymous

Oh okay thankyou(: I'd rather do that than draw out a circle everytime lol