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

hi there!

first we need to find out how much they are adding to each number to make the next number.

ex: 4 + 4 = 8, 8 + 8 = 16, and so on.

so continuing with 32,

32 + 32 = 64

64 + 64 = 128

128 + 128 = 256

256 + 256 = 512

4, 8, 16, 32, 64, 128, 256, 512

the 8th term of the sequence will be 512

hope this ! ~