SOLUTION: . If cosθ + sinθ = 2 cosθ ,then cosθ − sinθ = ? A. 2 sinθ B. cosθ 2 1 C. sinθ 2 1 D. None of the above

Algebra.Com
Question 886190: . If cosθ + sinθ = 2 cosθ ,then cosθ − sinθ = ?

A. 2 sinθ
B. cosθ
2
1

C. sinθ
2
1

D. None of the above
Answer by Edwin McCravy(20056)   (Show Source): You can put this solution on YOUR website!
cosθ + sinθ = 2cosθ
Add -cosθ to both sides of the equation

 cosθ + sinθ = 2cosθ
-cosθ          -cosθ
--------------------
        sinθ =  cosθ

Add -sinθ to both sides of the equation:

        sinθ =  cosθ
       -sinθ = -sinθ
       -------------
           0 =  cosθ - sinθ 

The answer is 0.  None of the above.

Edwin
RELATED QUESTIONS

The expression sin θ (cot θ - csc θ) is equivalent to? A) 2 Cos θ (answered by stanbon,lynnlo)
2 sinθ cosθ =... (answered by Alan3354)
2. For all θ where sin θ - cos θ ≠ 0, ((sin^2)(θ) -... (answered by solver91311)
prove each identity tanθ -1 = sin^2θ-cos^2θ/... (answered by MathLover1)
Prove that... (answered by Jc0110)
cosθ/sinθ=1/tanθ (answered by Aswathy)
Prove each Identity: a) sin^2(θ)/1−cosθ=1+cosθ b)... (answered by lwsshak3)
The expression sin θ(cotθ - cscθ) is equivalent to 1) cotθ -... (answered by stanbon)
Question 1= If Sinθ = 12/13, find the value of Sin^2 θ-cos^2 θ/ 2sinθ (answered by Alan3354)