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kashan123999
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Homework Statement
So I got towards the intergration of cosecx as -ln(cosecx + cotx),but in my coursebook it is ln(cosecx-cotx)?so how do you put that sign in the log :D
Homework Equations
∫[f(x)]/[F(x)] dx = ln|F(x)|+ c
The Attempt at a Solution
∫(cosecx) X (cosecx + cotx)/(cosecx + cotx) dx
∫[(cosecx)^2 + (cosecxcotx)]/(cosecx + cotx) dx
let cosecx + cot x = u → [-cosecxcotx - (cosecx)^2]dx = du
-[cosecxcotx + (cosecx)^2]dx = du
dx = -du/[cosecxcotx + (cosecx)^2]
so putting value of dx and (cosecx + cotx)
∫[(cosecxcotx) + (cosecx)^2] X (-du) / [(u) X {(cosecxcotx+ (cosecx)^2)}]
cosecxcotx + (cosecx)^2 will simply each other in numerator and denominator hence
∫(-du)/(u)
using reciprocal rule
-ln|u| + c
-ln|cosecx + cotx| + c
so in my courebook it is ln|cosecx - cotx|?? how to do that?