The integral is(adsbygoogle = window.adsbygoogle || []).push({});

[tex] I = \int_0^\pi (~3\cos^2(t) - 1~)\sin^2(t)~dt [/tex].

My TI-89 Titanium says [tex] I = 0 [/tex], but I know the answer (verified by hand and by mathematica) to be [tex] -\pi / 8 [/tex]. I am 100% sure I entered it correctly into the calculator. What gives?

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# Calculators TI-89 integration error?

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