Q. If x=log(cos(2y)+sin(2y)cos(2y)−sin(2y))tan(2y)=1+11−1. Then (vi), o, has the value(A) 21(B) −21(C) 41(D) −41
Simplify Right Side: First, let's simplify the right side of the equation. (1+11−1)=20=0=0
Analyze Left Side: Now, let's look at the left side of the equation.x=log(cos(2y)+sin(2y)cos(2y)−sin(2y))⋅tan(2y)Since x=0, we have:0=log(cos(2y)+sin(2y)cos(2y)−sin(2y))⋅tan(2y)
Solve for y - Tan Term: To find y, we need to solve for when the right side equals zero.log(cos(2y)+sin(2y)cos(2y)−sin(2y))⋅tan(2y)=0This can happen if either the log term or the tan term is zero.
Solve for y - Log Term: Let's check when tan(2y)=0.tan(2y)=0 when 2y=nπ, where n is an integer.But since tan is periodic with π, we only need to consider 2y=0 for the smallest solution.So, y=0×2=0
Correcting Mistake: Now let's check the log term. log(cos(2y)+sin(2y)cos(2y)−sin(2y))=0 This happens when cos(2y)+sin(2y)cos(2y)−sin(2y)=1
Correcting Mistake: Now let's check the log term. log(cos(y/2)+sin(y/2)cos(y/2)−sin(y/2))=0This happens when cos(y/2)+sin(y/2)cos(y/2)−sin(y/2)=1 Solving the equation cos(y/2)+sin(y/2)cos(y/2)−sin(y/2)=1cos(y/2)−sin(y/2)=cos(y/2)+sin(y/2)This simplifies to −sin(y/2)=sin(y/2)Which implies sin(y/2)=0
Correcting Mistake: Now let's check the log term. log(cos(y/2)+sin(y/2)cos(y/2)−sin(y/2))=0This happens when cos(y/2)+sin(y/2)cos(y/2)−sin(y/2)=1 Solving the equation cos(y/2)+sin(y/2)cos(y/2)−sin(y/2)=1cos(y/2)−sin(y/2)=cos(y/2)+sin(y/2)This simplifies to −sin(y/2)=sin(y/2)Which implies sin(y/2)=0sin(y/2)=0 when y/2=mπ, where m is an integer.Again, considering the smallest solution, y/2=0.So, cos(y/2)+sin(y/2)cos(y/2)−sin(y/2)=10
Correcting Mistake: Now let's check the log term. log(cos(y/2)+sin(y/2)cos(y/2)−sin(y/2))=0 This happens when cos(y/2)+sin(y/2)cos(y/2)−sin(y/2)=1 Solving the equation cos(y/2)+sin(y/2)cos(y/2)−sin(y/2)=1cos(y/2)−sin(y/2)=cos(y/2)+sin(y/2) This simplifies to −sin(y/2)=sin(y/2) Which implies sin(y/2)=0sin(y/2)=0 when y/2=mπ, where m is an integer. Again, considering the smallest solution, y/2=0. So, cos(y/2)+sin(y/2)cos(y/2)−sin(y/2)=10 Both the tan term and the log term give us cos(y/2)+sin(y/2)cos(y/2)−sin(y/2)=11 as a solution. However, we made a mistake in the simplification of the log term; it should not simplify to cos(y/2)+sin(y/2)cos(y/2)−sin(y/2)=12 but to a value that makes the argument of the log equal to cos(y/2)+sin(y/2)cos(y/2)−sin(y/2)=12. We need to correct this.
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