Number of solutions of tanx +secx=2cosx lying in 0,2×180 is
Siddharthasahul , 7 Years ago
Grade 11
1 Answers
Arun
Last Activity: 7 Years ago
tan x + sec x = 2cos x So , (1+sin x) / cos x = 2cos x ==> 1 + sin x = 2 cos^2 x ==> 1 + sin x = 2(1-sin^2 x) ==> 2sin^2 x + sin x -1 = 0 ==> sin x = -1 or sin x = 1/2
So there are a total of 3 solutions I think.
Note: sin x = 1/2 has 2 solutions , 30 and 150 (in degrees) and sin x = -1 has one solution.
Provide a better Answer & Earn Cool Goodies
LIVE ONLINE CLASSES
Prepraring for the competition made easy just by live online class.
Full Live Access
Study Material
Live Doubts Solving
Daily Class Assignments
Ask a Doubt
Get your questions answered by the expert for free