Question

Solve the following for θ, in radians, where 0≤θ<2π.
6cos2(θ)+7cos(θ)−7=0

Answer 1

Answer:5.41

0.87 is correct

Explanation:

We can solve this quadratic equation in terms of cos(θ) by using the quadratic formula:

cos(θ) = (-b ± sqrt(b^2 - 4ac)) / 2a

where a = 6, b = 7, and c = -7. Substituting these values, we get:

cos(θ) = (-7 ± sqrt(7^2 - 4(6)(-7))) / 2(6)

cos(θ) = (-7 ± sqrt(169)) / 12

cos(θ) = (-7 ± 13) / 12

Therefore, we have two possible solutions: