Recent content by mjbc

Homework Statement dx/dt = k(a-x)(b-x) x(0)=0 The Attempt at a Solution dx/((a-x)(b-x)) = kdt Integral (dx/(ab-bx-ax+x^2)) = kt +C x/ab - (1/b)ln|x| - (1/a)ln|x| - (x^-1) = kt + C however, if i try to substitute x(0) = 0, i get the ln 0 please help i have no idea if i am doing this right

OK, So it's (sec x - tan x) / (sec x + tan x)(sec x -tan x) = (sec x - tan x) / 1 = sec x -tan x Thank you so much!

sec^2 (x) - tan^2 (x) = 1 but nothing's squared in the problem

Homework Statement Simplify: cosx / (1+sinx) 2. The attempt at a solution 1 / (sec x)(1+sin x) 1 / (sec x + (sin x / cos x)) 1 / (sec x + tan x) I know that the answer is sec x - tan x but don't know how to get there. Any help would be appreciated.