SOLUTION: How can I solve: ln(cosx)=-1 the answer I think is 1371.58

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Question 224522: How can I solve: ln(cosx)=-1
the answer I think is 1371.58
Answer by rapaljer(4671) About Me  (Show Source):
You can put this solution on YOUR website!
ln(cosx)=-1

First "undo" the ln by raising both sides as a power of e.

e%5E%28ln%28cosx%29%29=e%5E-1
cosx=e%5E-1

Next, undo the cos function by using the arccos function:
x=+arccos+%28e%5E-1%29

Using a calculator, I got 68.42 degrees. If the calculator is in radian mode, I got 1.19 radians.

R^2