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Expert: Sherry Wallin - 4/11/2011


Question
cos theta/1-sin theta

Answer
What is the question? Are you wanting to take the first derivative of cos x/(1-sin x)? [I used x instead of theta]

Use the quotient rule for derivatives:
the bottom times the derivative of the top minus the top times the derivative of the bottom, all over the bottom squared or
let cos x = f and let 1-sin x = g
and let h = (cos x)/(1-sin x) so you want h'(x)
h'(x) = (gf'-fg')/g^2
= (1-sinx)(-sinx)-cosx(-cosx)/(1-sinx)^2
= -sinx + sin^2x+cos^2x(1-sinx)^2
= (-sinx + 1)/(1-sinx)^2
= (1-sinx)/(1-sinx)^2
= 1/(1-sinx)

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Sherry Wallin

Expertise

I can answer most questions up through Calculus and some in Number Theory and Abstract Algebra.

Experience

I have had my Bachelor's Degree since 1987 and have been a teacher since 1988. I earned my Masters Degree in Mathematics May 2010. I have been teaching at the same community college since 2002.

Education/Credentials
I have taught 12 years at the community college level, medical college, and technical college as well as a high school instructor and alternative education instructor and charter school instructor.

Awards and Honors
Master's GPA 3.56 Bachelor's GPA 3.34 Post grad work not degree related GPA 4.0

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