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

i need points

step-by-step explanation:

sorry bubs

if gloria has "carry over" minutes, (that is, any minutes paid for but not used in a month can be applied to her payment for minutes in the next month,) her total usage for the three months is: total minutes = 320 + 243 + 489 = 1052 minutes number of 200 minute blocks = 1052/200 = 5 r52 (that is 5 with a remainder of 52) rounding up the number of 200 minute blocks gives her usage for the three months as 6 blocks. the cost for six blocks is 6 x $25 = $150 she also has 200 - 52 or 148 carry over minutes if gloria pays each month and unused minutes are lost, applying the rounding up procedure to each month gives: first month usage of 320 minutes rounds up to 2 blocks of 200 minutes for a payment of 2 x $25 = $50 second month usage of 243 minutes rounds up to 2 blocks of 200 minutes for a payment of 2 x $25 = $50 third month usage of 489 minutes rounds up to 3 blocks of 200 minutes for a payment of 3 x $25 = $75 total payments for the three months are $50 + $50 + $75 = $175 get the plan with carry over minutes!