+0  
 
0
31
1
avatar

If cos(theta) = -2/sqrt5, and theta is in quadrant II, find the exact value of tan(theta+ pi/4)

Guest Nov 25, 2018
 #1
avatar+92429 
+1

cos (theta)  = -2 / √5

sin theta =  1/√5

 

tan (theta + pi/4)   =

 

sin (theta + pi/4)

_______________  =

cos (theta + pi /4)

 

sin theta * cos pi/4   + cos theta * sin pi/4

_________________________________ =         

costheta * cos pi/4 -  sin theta * sin pi/4

 

 { sin pi/4 = cos pi/4 =  1 /√2 }

 

 

1/√2  [ sin theta + cos theta ]

_______________________  =

1 / √2 [ cos theta - sin theta ]

 

 

[ 1/√5  + (-2)/√5 ]

_______________   =

[ (-2)/√5  - 1/√5 ]  

 

 

[ 1 - 2 ]                  -1                 1 

________    =      ____     =    ___

[ -2 - 1 ]                  -3                3

 

 

 

cool cool cool

CPhill  Nov 25, 2018

10 Online Users

avatar
avatar

New Privacy Policy

We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive information about your use of our website.
For more information: our cookie policy and privacy policy.