# Trig Help (Inverse Functions)

• Nov 20th 2009, 04:27 PM
agent2421
Trig Help (Inverse Functions)

So this involves the use of 2 graphs:

Y = arccos x
y = arctan x

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The question is:

In looking at the sketches you have drawn in question 1, you should see that the inverse relations are not actually functions! Determine through investigation the domain of the trigonometric function, f(x) = sin x, over which the inverse of the trigonometric function, f -1 (x), is also a function. You may use technology if you wish.

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I have no idea how to do it... my teacher didn't explain this to us and he barely teaches us anything in class... I looked through the book but still don't understand it... Can someone please help me, I don't want the answer but how to find the answer, steps and maybe a final answer so I know how to do this from now on.

Thanks :)
• Nov 20th 2009, 11:33 PM
bigwave
basically relations (without parameters) do not pass the vertical line test...

arccos(x) and arctan(x) are functions [-1,1]
which is shown if graphed..

probably what they are trying to show is where relations can be functions within certain domains....

most functions that are reflected over the line y = x will no longer be 1 to 1

at least that what it appears anyway....
• Nov 21st 2009, 11:19 AM
agent2421
so how exactly should I answer the question?