Why do we write that the inverse function of sin is:
\[\sin ^{-1}\]since the inverse function of sin isn't \[\frac{ 1 }{ \sin }\]
the exponent of \(-1\) means the inverse of the function under composition, not the inverse of the number under multiplication
with numbers, \(a^{-1}=\frac{1}{a}\) because \[a\times a^{-1}=1\] and \(1\) is the identity under multiplication
the inverse of a function \(f^{-1}\) is the function that, when composed with \(f\) gives the identity function \(I(x)=x\)
that is, \[f^{-1}\circ f=I\]
means give the angle that has x for its sin that's not really true when you go further into trigonometry.
"means give the angle that has x for its sin"*
the operation is composition, not multiplication, and the identity is the identity function, not the number 1
the notation itself has nothing to do with trigonometry, it is the notation used for all functions for example if \(f(x)=2x-1\) then \(f^{-1}(x)=\frac{x+1}{2}\) not \(\frac{1}{2x-1}\)
if you really have trouble using sin^-1, use arcsin you will be well-understood
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