SOLUTION: It's been a while since I've taken any algebra class, so most of my problems revolve around a single missing part of the process. My only access to the internet right now is via my

Algebra ->  Graphs -> SOLUTION: It's been a while since I've taken any algebra class, so most of my problems revolve around a single missing part of the process. My only access to the internet right now is via my      Log On


   

Question 11178: It's been a while since I've taken any algebra class, so most of my problems revolve around a single missing part of the process. My only access to the internet right now is via my cell phone. I apologize for not using your preferred bracket method to point out the problem. I will display the problem the best I can.
(I'm not sure about the n; (could be pie?), the type on the sheet is a bit messed up. I'll use "»" to represent an exponent.)
Here's the problem:
((( Find f(n»r/4) if f(x) =
(-2 sin (2x))/3 + (5 cos (4x))/6 )))
The answer I have is (-3/2). I just have no idea how to get it.
Answer by longjonsilver(2297) About Me  (Show Source):
You can put this solution on YOUR website!
i think what you have here is find f%28pi%2F4%29 which is the radian measure corresponding to 45 degrees.

So, from (-2 sin(2x))/3 + (5 cos(4x))/6 we have
(-2sin(2*45))/3 + (5cos(4*45))/6
(-2sin(90))/3 + (5cos(180))/6
(-2(1))/3 + (5(-1))/6
-2/3 + (-5/6)
-2/3 - 5/6
-4/6 - 5/6
-9/6
-3/2

jon.