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Old May 19th, 2009, 08:38 PM
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Default Just a quick trig solving question...

i thought the question was simple and asks 'solve for sinx=-0.2 for 0<x<360'. I took inverse sin over to get get x=(inv)sin -0.2 but it gave me -11.53...? And im not sure how the mark scheme got 191.357 and 348.463.

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Old May 19th, 2009, 09:01 PM
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What you forgot is that a function has an inverse if and only if it is one to one. sin is only one to one for x between 0 and 90 degrees. Therefore the domain of the function must be restricted to those values. You did the problem right but your calculator gave you the refrence angle. Here's a hint: What's 360- 11?
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Old May 20th, 2009, 12:01 PM
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thanks.
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