Given that a is less than 0, then the point P (- the square of a-2,2-a) is in the () quadrant?

Given that a is less than 0, then the point P (- the square of a-2,2-a) is in the () quadrant?

second
We know that a is less than 0, so the square of - A - 2 is less than 0,
2-A is greater than 0
One minus one is in the second quadrant

A math problem in grade one of junior high school
At 8:00 a.m., a and B set out from a and B at the same time, facing each other. It is known that a's speed is 2 kilometers faster than B's. at 10:00 a.m., they are 38 kilometers apart. At 12:00 p.m., they meet again for 38 kilometers to find the distance between a and B

Solution: suppose B's speed is x, then a is x + 2. At 10 a.m., the distance between the two people is 38 km, which is the distance before meeting. At 12 noon, the two people get together 38 km, which is the distance after meeting. That is to say, a and B travel together in two hours: 38 + 38 = 76 km

If the average person completes 5 products per day in a workshop, the whole workshop overfulfils 30 products per day; if the average person completes 4 products per day, the whole workshop completes 20 less than the quota per day, the number of people in the workshop and the number of products completed in the quota per day are calculated

The number of people in the workshop is x, and the number of products per day is y
5x=y+30.1
4x=y-20.2
Formula 1-2
x=50.3
Substitute formula 3 into Formula 1
5*50=y+30
250=y+30
y=220

Given that a ^ 2 + B ^ 2 + C ^ 2 = 3, prove that 1 / (a ^ 2 + A + 1) + 1 / (b ^ 2 + B + 1) + 1 / (C ^ 2 + C + 1) ≥ 1
ABC is a positive number

In this case, we need to use the harmonic mean inequality (a1 + A2 +... + an) / N ≥ n / (1 / A1 + 1 / A2 +... + 1 / an) and the square mean greater than or equal to the arithmetic mean √ ((A1 & # 178; + A2 & # 178; +... + an & # 178;) / N) ≥ (a1 + A2 +... + an) / N, where n = 3, we have (a1 + A2 + a3) / 3 ≥ 3 / (1 / A1 + 1 / A2 + 1 / A3) ...

The diameter of a round flower bed is 10m, and a 2m wide circular path is paved around the flower bed. What is the area of the road?

The area of the path is the circular area
10 × 1 / 2 = 5m 5 + 2 = 7M
3.14×7×7-3.14×5×5
=3.14×24
=75.36 square meters

The interval where equation 9 / x = lgx must have a root is?
The class assignment book in the ability training and test of Senior One Education Press

Let f (x) = 9 / x-lgx;
f(9)=1-lg9=lg(10/9)>0;
f(10)=9/10-1=-1/10

Use a 108 cm long wire to make a cuboid frame. The ratio of the cuboid's length to width is 3:2:4. What's the cuboid's volume

The cuboid has 12 edges, of which there are four in length, width and height. It can be set as 3x in length, 2x in width and 4x in height
4（3x + 2x + 4x）= 108
36x = 108
x = 3
The cuboid is 9cm in length, 6cm in width and 12cm in height
Volume of cuboid v = 9 * 6 * 12 = 648 cubic centimeter

Decomposition factor: (a-b) (3a + b) & sup2; + (a + 3b) & sup2; (B-A)

How to calculate the area and mu of a triangle

Measure the length of three sides (in M)
Then use Helen's formula to find out the area in square meters
Then divide by 666,67 to get the number of mu

Given that loga x = 2, logb x = 1, logC x = 4, then logx (ABC) =?

logx (abc)= logx a + logx b + logx c
= 1/(loga x) + 1/(logb x) + 1/(logc x)
= 1/2 + 1/1 + 1/4
= 7/4