This is what my calculator is giving me:

$\displaystyle

\int {\cos (1 - x)dx = \sin (x - 1)}

$

This is obviously wrong. Could anyone explain why it's doing this?

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- Sep 28th 2008, 01:00 AMRedBarchettaTI-89 Integrating Incorrectly
This is what my calculator is giving me:

$\displaystyle

\int {\cos (1 - x)dx = \sin (x - 1)}

$

This is obviously wrong. Could anyone explain why it's doing this? - Sep 28th 2008, 01:06 AMMoo
- Sep 28th 2008, 01:08 AMChop Suey
It is not wrong.

$\displaystyle \int \cos{(1-x)} dx = -\sin{(1-x)} = \sin{(-(1-x))} = \sin{(x-1)}$

Recall that Sine is an odd function:

$\displaystyle \sin{(-u)} = -\sin{u}$ - Sep 28th 2008, 02:24 AMRedBarchetta
I didn't notice the change from (1-x) to (x-1) (Rofl)