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Calculus/Proving Identities

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Expert: Scotto - 6/23/2009


Question
sin^2x/(1-cosx)^2= 1+cosx/1-cosx

Answer
Take the right side and multiply the top and bottom by 1 - cosx.
The result is (1-cos^2(x))/(1-cosx)^2.

From one of the first identities in trig, it is known that
sin^2(x) + cos^2(x) = 1.

Using this, we can say that sin^2(x) = 1- cos^2(x).

That is what is in the numerator of the fraction in the first paragraph, so we can change  (1-cos^2(x))/(1-cosx)^2 into
sin^2(x)/(1-cosx)^2.

That looks like the left side, so we're 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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