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Expert: Scotto - 7/29/2008


Question
write tan(t) in terms of sin(t), given that (t) is in quadrant IV

Answer
In quadrant IV, sin() is negative and cos() is positive.  
Since tan()=sin()/cos(), this would make the tan() negative.

We know that [1] tan(t)=sin(t)/cos(t) and that
[2] sinē(t)+cosē(t) = 1.  

Using [2], we can say [3] cos(t)=√(1-sinē(t).
Put [3] back into the into [1] and you almost have it.  
All we have to do is check the sine.

Note that the sine of the answer is a negative over a positive, so the answer is negative, so we are done.

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Scotto

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Any kind of calculus question you want. I also have answered some questions in Physics (mass, momentum, falling bodies), Chemistry (charge, reactions, symbols, molecules), and Biology.

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Experience in the area: I have tutored students in all areas of mathematics for over 25 years. Education/Credentials: BSand MS in Mathematics from Oregon State University, where I completed sophomore course in Physics and Chemistry. I received both degrees with high honors. Awards and Honors: I have passed Actuarial tests 100, 110, and 135.

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Maybe not a publication, but I have respond to well oveer 7,500 questions on the PC. Well over 2,000 of them have been in calculus.

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I aquired well over 40 hours of upper division courses. This was well over the number that were required. I graduated with honors in both my BS and MS degree from Oregon State University. I was allowed to jump into a few junior level courses my sophomore year.

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I have been nominated as the expert of the month several times. All of my scores right now are at least a 9.8 average (out of 10).

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My past clients have been students at OSU, students at the college in South Seattle, referals from a company, friends and aquantenances, people from my church, and people like you from all over the world.

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