(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

x=sin(a) / cos(b)

a+b < pi/2

a>0, b>0

show that

da/dx = cos^3(b)cos(a) / cos(a+b)cos(a-b)

3. The attempt at a solution

dx/da = cos(a) / cos(b) therefore

da/dx = cos(b) / cos(a)

=cos^3(b)cos(a) / cos^2(b)cos^2(a)

However the denominator of the desired format = cos(a+b)cos(a-b) = cos^2(a)cos^2(b)-sin^2(a)sin^2(b)

Not sure how to get rid of the sin^2(a)sin^2(b) term...

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# Homework Help: X = sin(a)/cos(b), find da/dx

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