What does cos^-1 equal?

[Anonymous]

I'm doing a math problem and I've gotten down to the last part of [x=cos^-1] but I don't know how to do cos :/ HELP PLEASE XD

[electrollama]

There should be a button for it on your calculator. If not, get a different calculator. It's called an "inverse cosine" or "arc cosine" means what you get when you undo a cosine operation. For example, "cos (a) = b" can be re-written as "cos^-1 (b) = a" where a is usually an angle and b is just some number. You use it when you have the lengths of the side and the hypotenuse but you need the angle. If you're using windows, go to the calculator, go to "View", click "Scientific"; you should see "cos" on the left side. Click "Inv" (top left button) to switch that button to "cos^-1". You can't just do a cosine of an angle by hand. You need to memorize it if it's some special angle or use a calculator.

[Redstang88]

I could be wrong but I'm pretty sure its x=sin 1. Negative cosine is equal to sine. Not 100% sure without seeing the rest of the question but I think thats the answer, thats as far as you can solve without a calculator. shouldn't need one for trig functions.

[rthomas43]

This opinion is wrong in so many ways.

[RimaAmir]

im sorry but we did not learn the cos thing yet but Try mathway. com

[sp33d]

cos^-1 means the inverse of the cosine, which is arccos.
If x = arccosA (read x equals the arccos of A) then cos x = A.
That is relationship between functions and their inverses.

Cosine is a function so it also takes an argument, so your equation is meaningless row of symbols to me.

[rthomas43]

There is more to the problem.
If there is a number after the "-1", then the question is asking cos of some angle x equals that number.

[abc3643]

Arc cosine usually. Y= cos^-1 X means Y is the angle whose cosine = X, X = cos (Y).

[YazanAA]

You question doesn't make sense, you are missing something in that equation...

[YazanAA]

Why don't you post a picture of that problem so someone can solve it for you? Or at least someone can show you how to solve it

[Asker]

I found an online calculator that did it for me. Thanks :) now I just have one last portion of the equation and I can't even read it lol.

[YazanAA]

You are very welcome... But I'm sure that you are missing something because cos^-1 means the inverse of cos so: if cos^-1(A)=x then cos (x) = A... So according to this you can solve your problem

[Cowboy6666]

Show the basic question which you are solving to us.

This is senseless

[_Zara_]

I'm pretty sure cos^-1 is the inverse of cos

[puncakegirl]

Grab a calculator

[Asker]

Her why didn't I think of that :P don't you think if I had one I'd use it?

[puncakegirl]

Hmm well I suck at math

[Omar5881]

Cos (-1)=0.540,