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# inverse trig question watch

1. (Original post by Qer)
Is tan k positive for 0<k<pi/2?
it is positive

-pi/2 < k < 0?
in that range it is below the axes so it is negative?
Yep to both.
2. (Original post by Zacken)
Yep to both.
so for answer we have to write
it is same for cos but different for tan
3. (Original post by Qer)
so for answer we have to write
it is same for cos but different for tan
Well you have to say how it is different for tan.

How can you express tan k in terms of x, and how does this expression change if tan k is negative?
4. (Original post by Zacken)
Well you have to say how it is different for tan.

How can you express tan k in terms of x, and how does this expression change if tan k is negative?
just change sign?
5. (Original post by Qer)
just change sign?
Yes. But do you have an expression for tan k in terms of x?

6. i am ok with part a,b,c

struggling with part d
what i am done so far is that
from question we know g(x)=f(2x)
f(x)=arcsin x
so for g^-1 f(x) become1/2 sinx ( struggling at this point will it affects transformation)
g^-1 = 1/2 sin x
and range is 0 is less than or equal to g^-1 is less than or equal pi,....

(this is last question in which i face difficulty so after that i am going to start another exercise and after completing that exercise will tag you in post if i have some questions

7. (Original post by Zacken)
Yes. But do you have an expression for tan k in terms of x?
yeah
tanx=x/sqroot 1-x^2
8. (Original post by Qer)
f(x)=arcsin x
so for g^-1 f(x) become1/2 sinx ( struggling at this point will it affects transformation)
g^-1 = 1/2 sin x
and range is 0 is less than or equal to g^-1 is less than or equal pi,....
Huh?

so the inverse is which is

Now what is the domain of this function?? It would be the range of

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