Ikinda forgot my trig (kinda)
full explanations required, (including citation of the identity)
3 questions

1. and , then secθ=
2. and , then
3. if and , then

show all work

Since for , we have , so we take the positive root. Now,



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In the first quadrant, cosine is positive, so



and in turn,




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In the previous problem, we had , so we must have , which means