Difficult math problems!!!!!!!!!!!!!!!!!!!!!!!!!!

1.From the equation of the straight line we know c(-2 2,0) p(0,-8) so |pc|=√(|oc|^2+|op|^2)=6√22.From 1, we can see that c(-2 2,0) and d(0,1), so the slope of cd is k=(1-0) (0-(-2 2))=1 2 2, and the slope of the straight line is k=-2 2

k*k=-1

So DC is perpendicular to CP, and DC is the radius of the circle D.

So the straight line is tangent to the circle.

Another way to solve the second problem is to calculate the radius, calculate the dp, and then use the inverse theorem of the Pythagorean theorem to know that dpc is a right triangle, and then get the tangent.

3, see if you can't understand the question s= edc=scmd what is this... What is m...

1) Solution: from the meaning of the question and the diagram:

y=-80=-2x root number 2-8

Solution: x=-2 times the root number 2

y=-8, so oc=2 times the root number 2

op=8 in the right triangle cop, obtained by the Pythagorean theorem:

pc^2=oc^2+op^2

So pc = 6 times the root number 2

2) PC is tangent to the circle d.

Solution: It can be known from the meaning of the title and the diagram

pd=1+8=9

dc 2 = (2 times the root number 2-0) 2 + (0-1) 2 = 9 because pc = 6 times the root number 2

So dc 2 + pc 2 = pd 2 = 81

So the angle dcp = 90 degrees.

Because dc is the radius of the circle d.

So PC is tangent to the circle D.

3) Where is the point m?

What does m mean in "such that s=edc=scmd exists"?

True proposition.

But that's the basic concept of the absolute value......

In fact, this kind of problem is the distance from the origin 0 to b.

Think of it as an absolute value of 0-b (format a-b).

Thinking geometrically, the absolute value of a-b is ab

Because ab is always there, only 0 moves

There are two types of images - the same sign or different sign (needless to say, the absolute value ignores plus or minus), and when the same sign is used (drawing comprehension), the two points are on the same side of the origin.

then a-b can be seen as ao-bo= ab

To ensure that the distance is greater than 0

So add the absolute value, which is ab

When the sign is different (drawing comprehension), the two points are on the opposite side of the origin.

then a-b can be seen as ao-bo= ab

In summary, the distance between two points ab on the number axis = the absolute value of a-b.

Yes, there are two cases to consider: (1) the same side of the AB and (2) the opposite side of the AB.

.When the volume of ice increases by 1/10 after it is converted into water, it is to be considered as the unit 1, and the volume increased is 1/10 of the volume of ice.

2.An integer part with a fraction is the product of two reciprocal numbers, and the numerator of the fractional part is just 3 larger than the number of the integer part, and this fraction is up to (1 and 4/5).

The volume of water, the volume of increase is the volume of water, 1 and 4/5

Solution: (1) If the production of A kind of tiles x 10,000 pieces, then B kind (50-x) 10,000 pieces (< = is less than or equal to the meaning).

Solving this inequality gives 30<=x<=32

Because x is a positive integer.

So x takes 30, 31, 32

50-x=20,19,18.

Therefore, using the existing raw materials, the plant is able to complete the task as required. There are three production options:

Plan 1: Production of 30 A kinds of tiles and 20 B kinds of tiles;

Plan 2: Production of 31 A tiles and 19 B tiles;

Plan 3: Production of 32 A tiles and 18 B tiles.

2) The total cost is:

If x=300,000 yuan).

If x=310,000 yuan).

If x=320,000 yuan).

Therefore, the third production scheme designed (32 pieces of A type of tiles and 18 pieces of B type tiles) has the lowest total cost, and the minimum cost is 10,000 yuan.

If A x 10,000 pieces, then B (50-x) 10,000 pieces.

Solution x 35

2x+5(50-x) 145, the solution is x 35 so x = 35, 50-35 = 150,000 pieces.

10,000 yuan answer: to complete the task, there is only 1 plan, A and B are 35, 15 each, and the cost is 690,000 yuan.

Solution: (1) If the production of a kind of brick x 10,000 pieces, then B kind (50-x) 10,000 pieces can be solved by this inequality group 30<=x<=32 and because x 0, so x=30,31,32 50-x=20,19,18

So there are three production options:

Plan 1: Production of 30 A kinds of tiles and 20 B kinds of tiles;

Plan 2: Production of 31 A tiles and 19 B tiles;

Plan 3: Production of 32 A tiles and 18 B tiles.

2) The total cost is:

If x=300,000 yuan).

If x=310,000 yuan).

If x=320,000 yuan).

Therefore, the third production scheme designed (32 pieces of A type of tiles and 18 pieces of B type tiles) has the lowest total cost, and the minimum cost is 10,000 yuan.

Solution: (1) If the production of X bricks of A is established, then the production of B kinds of tiles (50-X) blocks.

Solution: x=29,30,31,32

50-x=21，20，19，18

There are four options.

Plan 1: Production of 29 pieces of type A tiles and 21 pieces of type B.

Plan 2: Production of 30 pieces of A type tiles and 20 pieces of B species.

Plan 3: Production of 31 pieces of A type of tiles and 19 pieces of B species.

Plan 4: Production of 32 pieces of A type of tiles and 18 pieces of B species.

2) Set: The total cost is w

w=k=y decreases as x increases.

When x=32.

y has a minimum value = 10,000 yuan).

Option 4 has the lowest total cost and the lowest cost is RMB.

ps: I don't know if the count is correct, but it shouldn't be a problem.

Obviously, when m is fixed above and below the ellipse, the angle f1mf2 is the largest (this can be proved), so cos=(2a-4c) 2a0, so a-2c0

1-2e²≤0e∈[√2

, 8*8=64, so the root number 59 is between 7 and 8, add 6 to each number, and you get 132Solve the inequality to get the solution set x"a 3, because there can only be two positive integers (there are no two inequalities, so you can only take 0), you get 2"a 3<3, get, 6"a<9

3.If you need to rent a 48-seater passenger car x cars, you need to rent a 64-seater passenger car (x-1) When renting a 64-seater passenger car, the car that is not full still has 64 (x-1)-48x, which is reduced to (16x-64) empty seats (expressed by an algebraic formula with x) From the title, the inequality group can be obtained:

16x-64＞0

16x-64＜32.

Solution: 4 x 6

x is an integer, x=5

Therefore, it is necessary to rent 5 48-seater buses

So the answer is: (x-1), (16x-64), 16x-64 016x-64 32

5 (2) The cost of renting a 48-seater bus is 5 250 = 1250 (yuan), and the cost of renting a 64-seater bus is (5-1) 300 = 1200 (yuan), 1200 1250, it is more cost-effective to rent a 64-seater bus Therefore, it is more cost-effective to rent a 64-seater bus Refer to jyeeo4Because 36 41 49

Let 41=6+k 0 k 1

41﹚²＝6+k﹚²

41=36+12k+k²

41≈36+12k

k≈5／12

So 41 6+5 12 6+

2）m≈ a+b/2a

1, square meters).

4=2 (pcs) ......2

10 cm²).

3, square centimeters).

The Chinese teacher is Xiaohong: 1 1 3=3

The math teacher is red: 1 3 11 = 11 3

The age ratio of Chinese teachers to math teachers is: 3:11 3=9:11

Let the age of the Chinese teacher be X, the age of the Math teacher will be Y, and the age of Xiaohong will be A.

then the following two equations are combined:

1/3x=a

3/11y=a

Solution: 1 3xa=3 11ya

1/3x=3/11y

x/y=9/11

Therefore, the age ratio of Chinese teachers to math teachers is 9:11

There are x soldiers and y fruits: 3x+20=y, 4x-25=y, x=45 people, 155 fruits.

Set up x soldiers and y fruits.

Then 3x+20=y

4x-25=y

Solution x=45

y=155

3 per person, the remaining 20 and the 25 imaginary ones that were brought together were added to Jian Xun's total of 45 bridge relatives, and these 45 were divided into 1 per person.

20+25) (4-3) = 45 people.

45*3+20=155.

The first day increase = the first day of the most ** - the first day of the lowest price = (the first day opening price + the first day opening price;

The next day's increase = the next day's highest** - the next day's lowest price = (the next day's opening price + the next day's opening price;

The third day increase = the third day most** - the third day low price = (the third day opening price + 0) - (the third day opening price;

The average increase over the three days = (

Opening price = x yuan.

Day 1: Maxmax1=x1+, Lowest min1=, (max1-min1) 2=

Day 2: Max2=x2+, min2=,(max2-min2) 2=

Day 3: Max3=x3, min3=, (max3-min3) 2=

Average increase: (RMB.)

Let the opening price be x, then the first day is the lowest price (, the second day is the most (x + the lowest price is (, the third day is the most ** x, the lowest price is (