can someone help me with this trig problem please.

AuburnMathTutor
Thu, 13 May 2010 23:45:58 +0000

This is not the right place for this.

Use the rule that sin(2x) = 2sin(x)cos(x).

Let x = 22.5. Then 2x = 45 and

8sin(22.5)cos(22.5) = 4 * 2sin(22.5)cos(22.5) = 4 * sin(45) = 4 sqrt(2)/2 = 2 sqrt(2).

Let me know if I made a mistake.