Rush for answers and processes, rushes, processes and answers

Solution: Let x + y = 3, let x = 3cos, y = 3sin let k = y (x+2).

kx+2k-y=0

3kcosα-√3sinα=-2k

3sinα-√3kcosα=2k

( 3) +3k) ]sin( -=2k,(where, tan =k)

3+3k²)sin(α-=2k

sin(α-=2k/√(3+3k²)

1≤sin(α-1

sin²(α1

4k²/(3+3k²)≤1

3k²+3≥4k²

k²≤3√3≤k≤√3

The maximum value of y (x+2) is 3 and the minimum value is -3

3.Let the minimum inner angle be x

x+2x+2x-20=180

x=40°4.A=90- B=90-35=55°Qingwei Cruises ACD=90- A=90-55=35°

Let the minimum inner angle of the summoner be x, the maximum inner angle of the chain concealment is 2x, and the final inner angle is 2x-20, and the equation x plus 2x plus 2x-20 is equal to 180 to calculate x

Let the profit of daily purchase of x copies be y

When x<200

The profit is (*30 = 24x.)

When 200 < = x < = 300

20-day profit (

10-day profit 【(

So the profit for a month is a total of 3200 + 8x when x>300

20-day profit (

10-day profit 【(

So, the profit of a month is 12800 -24x, draw the piecewise function image in the coordinate system, find the vertex is the highest profit, and the x value corresponding to the vertex is the number of copies to be entered.

x=300 300 per day, the maximum profit is 5600 yuan.

Buy 300 copies a day.

Their biggest profit in a month is:

5600 (yuan).

Solution, the newspaper that cannot be sold loses yuan per copy. Compare with the sold copy to pay a dollar per copy, order x copies, 200 x 300

Profit ==24x-16x+3200

3200+8x

When x=300, the profit is the largest, and the profit = 3200 + 300 8 = 5600 yuan.

Set x servings per day, x between 200-300.

Profit = simplified to 8x + 3200, to maximize profit, it is x maximum, x = 300

3 and 3 4x3 2) x (5 and 2 3x1).

Root number handicap 7 - root number noisy 3) x (root number 7 + root number 3)] x [(root number 7 - root number 3) x (root number 7 + root number 3)],