Solve on the interval [0,2pi) 2cos^2x+3cos x+1=0

π, 2π/3, 4π/3

Step-by-step explanation:

2cos²(x)+3cos(x)+1=0

1) Lets give cos x=y

So, we can rewrite our equation

2y²+3y+1=0

(2y+1)(y+1)=0

2y+1=0 or y+1=0

2y+1=0, 2y= -1 , y = -1/2

y+1=0, y= - 1

2) cos(x)= - 1, x=π

cos(x)= - 1/2, x=2π/3 or 4π/3

first option

a function is a relation in which an input is paired with exactly one output.

so, let's find the right answer.

in our first option, our inputs are january, february, and march. the outputs are 30, 28, and 25. each input has it's own output. this is correct!

our second option we know is incorrect, because ms. valverade has two outputs, dogs and cats. this is not a function.

our third option is incorrect as well. the yellow square has two ouputs, the square and the triangle.

lastly, in our fourth option, we see the number 7 two times with a different output. therefore, this is not a function.

remember: each input must be paired with only one output!

answer: input the dimensions of the room to be painted. click the button to calculate the amount of paint and man-hours needed for this job.

interior paint coverage depends on the brand of paint used. the coverage amount is listed on the label of the paint can. use this to adjust the values in the paint coverage section below. paint usually is applied at 350 to 400 square feet per gallon (primer at 200 to 300 square feet per gallon).

step-by-step explanation: