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# inverse trig function watch

1. i am just watching a tutorial on the internet about their graph.
for example
graph of sinx
it says we cant take inverse of that function because it is many to one ...we have to make it to one to one for inverse ... so we restricted it in the range
between -90 and 90 and
then he solve a question
arcsin (-sqroot2/2)
he says we have to give answer in range -90 to 90 because we already know range from graph

my question is why we only give an answer in that range as we can make graph one to one in other range as we also make graph one to one in range 90 to 270 .....???
2. (Original post by Qer)
i am just watching a tutorial on the internet about their graph.
for example
graph of sinx
it says we cant take inverse of that function because it is many to one ...we have to make it to one to one for inverse ... so we restricted it in the range
between -90 and 90 and
then he solve a question
arcsin (-sqroot2/2)
he says we have to give answer in range -90 to 90 because we already know range from graph

my question is why we only give an answer in that range as we can make graph one to one in other range as we also make graph one to one in range 90 to 270 .....???
Because they are sticking to the basic properties by telling you to do it between -90 and 90 as it is centred around 0 here whereas for any other domain isn't, and this makes things easier.

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Updated: July 25, 2017
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