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# C3 - State the Domain watch

1. Hiya,

Having trouble with C3 questions on Domain . Already tried searching for an answer, but found nothing that makes any sense.

I understand Range means relative to the y-axis and Domain to the x-axis.

Take for example:

http://www.imagebam.com/image/56658d64230728

I know how to show what the inverse function is, but I have no idea how you get the domain as -1 ≤ x ≤ 3.

2. You must first find the range for the first function. 1+ 2sinx so the highest y value is 3 and the lowest is -1. And because the "arc" graphs are inverse, the domain for one is the range of the other and vice versa.
3. You should recall that the domain of is the same as the range of .
4. (Original post by i_hate_examz)
Hiya,

Having trouble with C3 questions on Domain . Already tried searching for an answer, but found nothing that makes any sense.

I understand Range means relative to the y-axis and Domain to the x-axis.

Take for example:

http://www.imagebam.com/image/56658d64230728

I know how to show what the inverse function is, but I have no idea how you get the domain as -1 ≤ x ≤ 3.

-1/2pi≤sin^-1(x-1/2)≤ 1/2pi

sin(-1/2pi)≤(x-1/2)≤sin(1/2pi)

-1≤(x-1/2)≤1
-2≤x-1≤2
-1≤x≤3 -----> the domain you wanted.
5. Domain of the inverse function is the range of the normal function.

Range of normal function is that x is greater than/equal to -1, and less than/ equal to 3, as max of sin is 1, and min of sin is -1.

6. Ah... got it

Thanks !
7. would the range of the f(x) therefore give the domain of f-1(x)???

by the way does this only apply for sine graphs or can it be used for linear lines aswel

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