If the image of quadratic function y = 2x + ax + B passes through (2,3) points and its vertex is on the line y = 3x-2, then a and B are obtained

3 = 2 × 2 ^ 2 + 2A + B vertex coordinate formula (- B / 2a, (4ac-b ^ 2) / 4A) (4 × 2 × B-A ^ 2) / (4 × 2) = 3 × (- A / (2 × 2)) - 2, a = - 4, B = 3 or a = - 6, B = 7

An object with a mass of M = 0.20kg is still on a rough horizontal plane under the action of F1 and F2 forces. The maximum static friction between the object and the horizontal plane is 0.6N,
Where F1 = 0.6N, then F2 cannot be (). A1.3n B 0.7n C 0.6N D 0.2N

Choose a for this topic
The sum of the two forces is greater than the third force, and the difference between the two forces is less than the third force

A positive number plus a negative number equals?

If positive = negative, then positive + negative = 0
If positive number > negative number, then positive number + negative number = positive number
If it's a positive number

As shown in the figure, the mass of the ball is m, the tube with smooth inner wall is bent into a circular track and placed vertically, and the mass of the guide rail is 2m, so that the ball can roll in the tube. When the ball moves to the highest point, the tube just needs to leave the ground. At this time, how fast is the ball? (rail radius is R)

Because when the ball is at the highest point, the pipe just leaves the ground, and the supporting force of the ground is zero. According to the copoint force balance, the force of the ball on the pipe is f = 2mg, and the direction is vertical. According to Newton's second law, the solution is mg + F = mv2r, and the solution is v = 3gr. A: at this time, the velocity of the ball is 3gr

Let the sum of the first n terms of the arithmetic sequence {an} (n ∈ positive integer) be Sn, which is a monotone increasing sequence. If S4 ≥ 10 and S5 ≤ 15, then the value range of A4 is
Just calculate the minimum

As known, the tolerance D of sequence is positive
Because A1 = a4-3d, A2 = a4-2d, A3 = a4-d, A5 = A4 + D,
So S4 = a1 + A2 + a3 + A4 = 4a4-6d > = 10,
S5=5a4-5d

A car moves in a straight line at a constant speed of 25m / s, and then moves in a straight line at a constant deceleration with an acceleration of 5m / S2 after braking. What is the displacement ratio of the car passing through 3S and 6S after braking

When five seconds, the car has stopped, so S3 seconds = (V end) * (V end) - (V beginning) * (V beginning) = 625-100 = 525, S6 seconds = (V end) * (V end) - (V beginning) * (V beginning) = 100-0 = 100, so S3 seconds: S6 seconds = 21:4

Xiaoming jumps i218 times, 67 times less than Xiaogang's, and 4 times more than Xiaoqiang's

Let Xiaogang jump x times
218=3x-67
3x=285
x=95
Xiao gang jumped 95 times
Let Xiaoqiang jump y times
218=2y+4
2y=214
y=107
That is: Xiaoqiang jumped 107 times

1.When he was a child,he often __ and nobady believed him including his parents
A.lay B.lied C.laid D.lain
2.Put some wet towels the door to keep the smoke out.
A.at the bottom of B.in the bottom of C.on the bottom of D.along the bottom of
3.If he us,we can't win the match
A.join B.won't join C.doesn't join D.is joining
4.Good reading skills are quite uesful our students.
A.to B.for C.on D.at
5.Parents don't allow their children out alone at night.
A.to go B.go C.going D.gone
6.Jenny can't come to answer the phone.She _ a bath.
A.washes B.has C.is washing D.is having
7.__ sure you know the fire exit nearest to your room.
A.To be B.Be C.Don't be D.Not be
Fill in the blanks with the appropriate form in brackets
1.If you have any questions,you may ask for information from the _ (receive) desk
2.Blind people use their listening skills more than those with _ (see)
3.Have you decided on the __ (locate)of the new building yet?
4.A few minutes _ (late),all the people were safe out of the theatre on fire.
5.Will you please _ (explanation) the third paragraph again for us?
6.He usually cares for others more than _ (he)

1.When he was a child,he often __ B__ and nobady believed him including his parents
A.lay B.lied C.laid D.lain
2.Put some wet towels __ A__ the door to keep the smoke out.
A.at the bottom of B.in the bottom of C.on the bottom of D.along the bottom of
3.If he __ C__ us,we can't win the match
A.join B.won't join C.doesn't join D.is joining
4.Good reading skills are quite uesful __ B__ our students.
A.to B.for C.on D.at
5.Parents don't allow their children __ A__ out alone at night.
A.to go B.go C.going D.gone
6.Jenny can't come to answer the phone.She ___ D__ a bath.
A.washes B.has C.is washing D.is having
7.___ A___ sure you know the fire exit nearest to your room.
A.To be B.Be C.Don't be D.Not be
Fill in the blanks with the appropriate form in brackets
1.If you have any questions,you may ask for information from the ___ received__ (receive) desk
2.Blind people use their listening skills more than those with __ sight_ (see)
3.Have you decided on the __ locution__ (locate)of the new building yet?
4.A few minutes __ later_ (late),all the people were safe out of the theatre on fire.
5.Will you please __ explain___ (explanation) the third paragraph again for us?
6.He usually cares for others more than ___ himself__ (he)

A point representing an integer on a number axis is called an integral point. The unit length on a certain number axis is one centimeter. If a line segment AB of eight centimeters is drawn on the number axis, then the number of integral points covered by the line segment AB is?

Solving two math problems
1、 Just now, my family uses 37 degrees of electricity in May and 35 degrees in March. Which month uses more electricity every day? (expressed in scores)
2、 Mom and Sasa go shopping in Zhongbai supermarket, it takes 12.5% of the time to go and 10.7% of the time to come back. Do they walk fast when they go or when they come back?

37 / 30 > 35 / 30, so the average daily electricity consumption is more in May
2. Because the distance is the same, the less time it takes, the faster it goes. 5 / 12 < 7 / 10, so it goes faster

If the image of quadratic function y = 2x + ax + B passes through (2,3) points and its vertex is on the line y = 3x-2, then a and B are obtained