1 A 2 C 3D 4 A 5 B 6D 7D 8 C 9 C 10D 1 1 C 12 C

Second, fill in the blanks

13. 14.24000 15.2 16.

Third, answer questions.

17, solution: remember that the opposite sides of Angle A, Angle B and Angle C are A, B and C respectively.

( 1)

1 point

2 points

4 points

6 points

(2) From the cosine theorem, we can get

,

, 8 points

. 10 point

18, solution: (1) The possible values are 3,4,52 points.

3 4 5

8 points

(2) 12 points

19. Solutions (1)

Face to face

face

Take the midpoint h plane.

face

AH is 3 minutes from point A to the ground.

The distance from AH = 1 A to the surface is 1.6 minutes.

2), a little work

And 10 integral.

Therefore, there is a real number that makes and holds at the same time.

12 point

20. Solution: (1) 1.

x -4

-3 (-3,- 1) - 1 (- 1, )

- 0 + 0 -

minimum value

maximum

-2

4 points

The maximum value is 0 and the minimum value is -2 6 points.

(2)

set up

, so there is no extreme point of 8 points.

When,

Decreasing interval: increasing interval:

There are two extremes.

9 points

When,

Decreasing interval: increasing interval:

There is an extreme point.

10 point

To sum up: there is an extreme point; There are two extreme points; 12 point zero point.

2 1. Solution: Let A be simultaneous.

2 points

(Ⅰ)

=

4 points

(Ⅱ) (1) Tangent to point A: ①

Tangent line passing through point B: ②

At the same time ①②n points (

So n points are eight points on a straight line.

(2)