SOLUTION: could you please help me find sin(2x) and cos(2x)
sinx= 3/√10 and pi/2 < x < pi
the answers that I was getting were very wrong
Algebra ->
Trigonometry-basics
-> SOLUTION: could you please help me find sin(2x) and cos(2x)
sinx= 3/√10 and pi/2 < x < pi
the answers that I was getting were very wrong
Log On
Question 1094866: could you please help me find sin(2x) and cos(2x)
sinx= 3/√10 and pi/2 < x < pi
the answers that I was getting were very wrong Found 2 solutions by Alan3354, rothauserc:Answer by Alan3354(69443) (Show Source):
You can put this solution on YOUR website! What answers did you get, and how did you get them?
================
How do you know they're "very wrong" and not just wrong?
You can put this solution on YOUR website! the inverse sin of 3/square root(10) = 71.5651
:
x = 180 - 71.5651 = 108.4349
:
sin(2x) = sin(2 * 108.4349) = -0.6
:
cos(2x) = cos(2 * 108.4349) = -0.8
:
