MATH SOLVE

2 months ago

Q:
# Which of the following are solutions to the equation 2cos^2(x) - 1 = 0? Check all that apply.A. 3pi/4B. 15pi/4C. pi/8D. -7/pi/4

Accepted Solution

A:

The equation 2cos^2(x) - 1 = 0 we manupulate by adding 1 to both sides and then dividing both sides by 2.

2cos^2(x) - 1 = 0

2cos^2(x) = 1

cos^2(x) = 1/2

cos(x) = ±√1/2

cos(x) = ±√(2)/2

The answers to your question are A. 3pi/4, B. 15pi/4, and D. -7pi/4 as they all are angles with a reference angle of pi/4. They will have a cosine ratio of √(2)/2 or -√(2)/2

2cos^2(x) - 1 = 0

2cos^2(x) = 1

cos^2(x) = 1/2

cos(x) = ±√1/2

cos(x) = ±√(2)/2

The answers to your question are A. 3pi/4, B. 15pi/4, and D. -7pi/4 as they all are angles with a reference angle of pi/4. They will have a cosine ratio of √(2)/2 or -√(2)/2