jp13aav: what is INV
this is the working out and answer to a question
θ = INV Sin0.75 = 48.6o
What does the INV mean?
inv stands for inverse.
for example
sine 30
o=0.5
so
Inverse sine 0.5 = 30
o Inverse sine 0.5 can also be referred to as arcsine 0.5 and it can be written a number of different ways.
the most common ways are
sin
-10.5 This is easily confused with (sin 0.5)
-1 (but it is completley different in meaning) And for this reason I think this notation is silly but it is the most common notation.
and
asin0.5 I like this notation much better but it is less common.
The inv in your question is not proper maths notation it is just trying to give you guidance for how it is done on a calculator.
If you look at the sin button on your calculator, above it probably in a different colour is sin
-1 To use this key, you have to press another key usually in the top left corner of your calculator first.
It will be marked as
INV or possibly
2nd Function That is the button that your INV is referring to.
Remember, before you do any of this make sure that your calculator is set to degrees. There should be a tiny little D at the top of your display panel. It will be there all the time unless you change it to something else.
To sum up
You have to press the INV key if you are looking for an angle.
+118653 
