How do you evaluate #cos(sin^1(1/4))# without a calculator?
1 Answer
Aug 29, 2016
Explanation:
Let
The given expression is
Instead of the principal a or any other value in Q4, if we choose a
value in Q3, wherein cosine is also negative, the answer will be #
sqrt 15/4#
For
An a in Q3 is
Yet, according to the convention for the choice of a as the principal
value, the sign is positive...
