Question

@Cosmichaotic and @surjithayer
May you please check this one?
I got C.

Answer 1

This is how I got it:

10 cosx=6.4
cosx=.64=cos 50 deg
x=50 deg

Answer 2

Can you show me how you got cosx=.64=cos 50 deg

Answer 3

I think your right of course here, but how did you simplify: cosx=0.64

Answer 4

Calculator is life :D

Answer 5

Calculators are crutches to mental growth!

Answer 6

That's why I use em alla time and don't know how to do this now.

Answer 7

Shhhh.. We're best friends! IT's a bittersweet process xD

Answer 8

you can use logarithmic tables.