ExamBro
ExamBro
TS EAMCET · Maths · Trigonometric Equations

The general solution of the equation \(\sqrt{6-5 \cos x+7 \sin ^2 x}-\cos x=0\) also satisfies the equation

  1. A \(\tan x+\cot x=2\)
  2. B \(\cot x+\operatorname{cosec} x=1\)
  3. C \(\tan x+\sec x=1\)
  4. D \(\sec x+\operatorname{cosec} x=2\)
Verified Solution

Answer & Solution

Correct Answer

(C) \(\tan x+\sec x=1\)

Step-by-step Solution

Detailed explanation

\(\sqrt{6-5 \cos x+7 \sin ^2 x}=\cos x\) (Condition: \(\cos x \ge 0\)) \(6-5 \cos x+7(1-\cos^2 x)=\cos^2 x\) \(8 \cos^2 x+5 \cos x-13=0\) \((8 \cos x+13)(\cos x-1)=0\) \(\cos x=1\) (since \(\cos x \ge 0\) and \(\cos x \ne -13/8\)) Check option C: \(\tan x+\sec x=1\)…