Question

Check my answer please !
Find the approximate angle measure of the following: cos-1 (¼)
A. 25º >C. 90º<
B. 75º D. 15º

Answer 1

Im not sure exactly how to explain it. Do you have a scientific calculator?

Answer 2

You want to find the angle of Cosine that has the ratio 1/4

Answer 3

Cosine A = 1/4

Where A stands for the angle

Answer 4

C is wrong peach

Answer 5

Take the inverse of cosine for .25
cos-1(.25) =

Answer 6

To summarize a bit:

We are given: "The cosine of Angle A is 1/4."

We are to find the angle, A.

We write angle A as follows:\[A=\cos ^{-1} \frac{ 1 }{ 4 }\]

Answer 7

or as you already have:\[A=\cos ^{-1} 0.25\]

Answer 8

@peachbubs: Have you done this kind of work before?

Do you want the angle A in degrees or in radians?

Answer 9

do you know where to find the key on your calculator that will find the inverse cosine of a given cosine ratio (1/4)?

Answer 10

Peachie: Please, pretty please, let those helping you know if you're going to log off OpenStudy in the middle of a discussion. Thanks.

Answer 11

Sorry, nobody was answering my question when I was online and I thought I closed it before logging. I need an answer in degrees and I'm not entirely familiar with things like this, no. Is cosh the inverse of cosine ?

Answer 12

I've given you considerable info already. Have you actually read through that info (above)? If so, please answer my question about functions that your calculator can evaluate.

Your calculator likely has a MODE key; find it, and set your calculator to DEGREES mode.

Answer 13

I found this out not long after saying I didn't know how to figure it out, but I have the answer now ! Thank you very much. uvu