Will mark ! find all solutions in the interval [0, 2π). cos2x + 2 cos x + 1 = 0 a. x = 2π b. x = π c. x = pi divided by four., seven pi divided by four. d. x = pi divided by two., three pi divided by two.

B

Step-by-step explanation:

cos²(x) + 2cos(x) + 1 = 0

Factor to get: (cos x + 1)² = 0

Set each factor equal to zero and solve :

cos x + 1 = 0    ⇒   cos x = -1          

Look at the Unit circle to find when cos = -1

cos = -1 at π

x = π

explanation:

previous steps have made pa≅ pb ≅ st ≅ su. setting the compass width to ab allows you to make tu the same length. then δstu ≅ δpab by the sss congruence postulate, and ∠p ≅ ∠s by the reason cpctc.

168

step-by-step explanation:

first off, we know that he drove 3.5 hours at a rate of 48 mph.

knowing that, we want to see how many miles he drove all-together.

in this case, we can just multiply 48 by 3.5.

48 * 3.5 = 168