Question #9043b

1 Answer
Dec 11, 2016

Use ln(u/v) = lnu-lnvln(uv)=lnulnv to simplify the process.

Explanation:

(If cc is a constant, then the whole thing is constant and the derivative is 00)

I will assume that cc is the independent variable. If we are differentiating with respect to some other variable, then we must apply the chain rule and multiply by the derivative of cc.

f(c) = ln((1+sinc)/(1-sinc)) = ln(1+sinc)-ln(1-sinc)f(c)=ln(1+sinc1sinc)=ln(1+sinc)ln(1sinc)

Now use d/(dc) (lnu) = 1/u (du)/(dc)ddc(lnu)=1ududc (chain rule) to get

f'(c) = 1/(1+sinc) * (cosc) - 1/(1-sinc) (-cosc)

= cosc/(1+sinc) + cosc/(1-sinc)

= (2cosc)/(1-sin^2c)

= 2/cosc = 2sec c.