# Trigless integral?

Is there a way to do this integral without substituting in sec?

int sqr(x^2-1)

Ive tried a bunch of things, but the only thing that works is using sec,

Is there any other method?

SammyS
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Is there a way to do this integral without substituting in sec?

int sqr(x^2-1)

Ive tried a bunch of things, but the only thing that works is using sec,

Is there any other method?
What's the problem with letting x = sec(θ) ?

Well, you can alternatively use the substitution: x = cosh(t) → dx = sinh(t) dt .