ksaimouli 4 years ago 3cosx+9=7 slove for x saifoooo help

1. ksaimouli

131.8 another one

2. ksaimouli

plx 73 plz

3. anonymous

$\color{red}{x}\color{blue}{\text{saifoo}}=\cos^{-1}(-\frac{2}{3})$

4. myininaya

I told you how to get the solutions $x=\cos^{-1}(\frac{-2}{3})+2n \pi$ Please ask me what you don't understand about how I got this? by the way n is an integer

5. anonymous

looks like 131.8 degrees if you are working in degrees

6. anonymous

hello myininaya!

7. myininaya

if you want degrees do +360 n

8. myininaya

and put your calc in degree mode for approximations

9. myininaya

hey sat

10. ksaimouli

how to get 228.19

11. anonymous

i am making truth tables. nothing could be more boring, but i have to do it t t t f f t f f arrghhh

12. ksaimouli

is i have to add 180 hhhhhhhhhh i dont know plz help

13. anonymous

subtract 131.8 from 360

14. anonymous

let me draw a picture

15. ksaimouli

ok

16. anonymous

|dw:1326938616923:dw|

17. myininaya

cos(x)=cos(-x)

18. anonymous

both those places on the circle have the same first coordinate, that is the same cosine. the first one you can get from the calculator, it is131.8 the other one you get from subtracting 131.8 from 360

19. myininaya

$\cos(131.8)=\cos(-131.8)=\cos(-131.8+360)$

20. anonymous

@myininaya is that a five o-clock shadow you're sporting?

21. ksaimouli

ok thx so ican sub 360 for everythink like thses problems