Integration By Substitution Problem (Trig)

KingKai
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Homework Statement



Integrate the following using substitution techniques

∫e3tcsc(e3t)cot(e3t) dt

Homework Equations



csc(t) = 1/sin(t)

cot(t) = 1/tan(t)

cot(t) = cos(t)/sin(t)

1 + cot2(t) = csc2(t)

The Attempt at a Solution



∫e3tcsc(e3t)cot(e3t) dt

set u = cot(e3t)

du = (3e3t)(- csc2(e3t)) dt


Make Substitution,


∫e3tcsc(e3t) (u) (1/(3e3t)(- csc2(e3t)) du



Whoops, csc does not cancel out..



My friend told me I had to make TWO substitutions, following this advice my head proceeded to explode.

After recollecting the pieces of my skull fragments and carefully gluing them together again, I posted this question.
 
on Phys.org
KingKai said:

Homework Statement



Integrate the following using substitution techniques

∫e3tcsc(e3t)cot(e3t) dt

Homework Equations



csc(t) = 1/sin(t)

cot(t) = 1/tan(t)

cot(t) = cos(t)/sin(t)

1 + cot2(t) = csc2(t)

The Attempt at a Solution



∫e3tcsc(e3t)cot(e3t) dt

set u = cot(e3t)

du = (3e3t)(- csc2(e3t)) dt


Make Substitution,


∫e3tcsc(e3t) (u) (1/(3e3t)(- csc2(e3t)) du



Whoops, csc does not cancel out..



My friend told me I had to make TWO substitutions, following this advice my head proceeded to explode.

After recollecting the pieces of my skull fragments and carefully gluing them together again, I posted this question.

I would be inclined to turn the cot and csc functions into their sine and cosine equivalents, and go from there.
 

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