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January 25, 2015

January 25, 2015

Posted by **chama** on Wednesday, March 14, 2012 at 11:02am.

- maths -
**Reiny**, Wednesday, March 14, 2012 at 11:08amprove sin (3Ø) = 3sin Ø - 4sin^3 Ø

LS = sin(2Ø + Ø)

= sin2Ø cosØ + cos2ØsinØ

= 2sinØcosØcosØ + (1-2sin^2 Ø)sinØ

= 2sinØ(1-sin^2 Ø) + sinØ - 2sin^3 Ø

= 2sinØ - 2sin^2 Ø + sinØ - 2sin^3 Ø

= 3sinØ - 4sin^2 Ø

= RS

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