What is #\cos ^{-1}(.60)#?

1 Answer
Write your answer here...
Start with a one sentence answer
Then teach the underlying concepts
Don't copy without citing sources
preview
?

Answer

Write a one sentence answer...

Answer:

Explanation

Explain in detail...

Explanation:

I want someone to double check my answer

Describe your changes (optional) 200

4
Jan 1, 2017

Answer:

#cos^-1 (0.6)= 53.1°#

Explanation:

Note that #cos^-1 # does not mean #1/cos# as we are used to in algebra.

#cos^-1# is the notation used for arc-cos.

#Cos 30° = 0.866 " "hArr" "cos^-1(0.866) = 30°#

In this case #cos^-1 (0.60)# is asking the question..

"Which angle has a #Cos# value of 0.60?"

The only way to determine this is with a calculator or tables.
Using a graph is possible, but not accurate enough.

Depending on which calculator you have, the following are possible key presses:

D.A.L. calculators:

shift #cos^-1 (0.6) =" larr# ( ) might not be needed on some models

The answer will be #53.1°#

Or #0.6" shift" cos^-1" "larr =# sign not needed, the answer #color(white)(...............................................)#appears immediately

The answer will be #53.1°#

Note that this is only the acute angle, the 1st quadrant angle.
In the 4th quadrant, #Cos 306.9° = 0.6#

Was this helpful? Let the contributor know!
1500
Impact of this question
Answer impact map
251 views around the world
You can reuse this answer
Creative Commons License