Can you explain this to me? I don't understand the cos to the negative first power. Problem attached

Question

kymber · Answer

attachment

lgbasallote · Answer

it means arc cosine...it was used to cancel the cos(T) because the arc cosine-ing a cosine cancels the cosine...and you need to cancel it to isolate T. oh i hope my explanation is clear :(

anonymous · Answer

that means arccos which is an angle

kymber · Answer

Yeah, I know it was used to cancel it out, but I don't understand how they got the answer. :p

lgbasallote · Answer

arc cosine of -(0.1278) it was inputted in a scientific calculator

anonymous · Answer

calculator has a
$$\cos^{-1}$$
button

anonymous · Answer

like tan(pi/4) =1 when you take arctan of tan see on right side you will get arctan(1) which is  pi/4

anonymous · Answer

just don't confuse
$$\cos^{-1}$$ with
$$\frac{1}{\cos}$$
They are not the same

kymber · Answer

Oooh. I don't think my calculator has that button. I thought you had to like work it out

kymber · Answer

So I can't do this unless I have a special calculator?

anonymous · Answer

there is a buttom

kymber · Answer

I think i have a special calculator in the drawer in my bathroom. I'mma go check

anonymous · Answer

you can also type arccos(-0.1278) into google

anonymous · Answer

button

anonymous · Answer

that will give you the answer in radians though, so multiply google's answer by 180/pi

lgbasallote · Answer

normally it's shift + cos

lgbasallote · Answer

in scientific calculators

kymber · Answer

I didn't find it. :( But I'm sure there's an online calculator that'll work! Anways thanks guys! :]

anonymous · Answer

@Dockworker You can also add the words "in degrees" at the end.

anonymous · Answer

oh cool, didn't know that

kymber · Answer

Google is such fabulous website

anonymous · Answer

Google scares me sometimes with what it can do.

kymber · Answer

Haha! :D