Finding math junior high school function estimation problems...

Add two questions.

1) Observe the ** in the question, it can be seen that the average yield of each B fruit tree z (kg) and the number of planted trees x (trees) conform to a function, let the average yield of each B fruit tree z (kg) and the number of planted trees x (trees) function relationship is: z=kx+b, (60,32) and (80,26) into the analytic formula to obtain: 60k+b=32 80k+b=26, the solution:

k= b=50, the functional relationship between the average yield z (kg) per B fruit tree and the number of planted trees x (trees) is: z=;

(80,26), (92, substituting z=, the equation holds;

2) If M fruit trees of A are planted, 200-m fruit trees of B will be planted, w=m(, the number of fruit trees planted in A does not exceed 40% of the total, the number of fruit trees planted in A does not exceed 200 40%=80, and when Xiao Wang plants 80 fruit trees of type A, the total yield of the orchard is the largest, and the maximum value is: w=;

3) According to the title:

3600 1 6 6+3600 1 3 (1-a%) 6+3600 (1-1 6 -1 3) 1-a%) (1+, solution: a 19

a=19．

This can be done using the mantissa method, such as:

The mantissa should be 0

This kind of problem is done with equations, the two sides are equal, and the equation can be solved. The left side of the equation is the original income, and the right side is the actual profit + loss, the specific equation is: 3600*6=6*3600*1 6+6*(1-a%)+6*(1-a%)*1+, solving the equation is your answer.

I think I'll give you a quadratic function.

Haha, it's very difficult for you to ask this question, so I suggest you explain the example question.

You need to ask clear questions.

The middle school math estimation method commonly uses the pinch method: that is, find a larger one than it and one smaller than it, and then narrow it out step by step to find the approximate value. For example: Estimate the size of 5.

Because 4< 5< 9

So: 2< 5<3

So: < 5 <

So: 5 approx.

Good answer on the first floor. However, estimating is about being fast, which seems a bit complicated.

I'll send it to your mailbox.。。

Original formula = [2a (a-1)-a (a-i)]*1 a=a (a-1)*1 a

1/(a-1)

When a = root number 2+1.

Original = root number 2-1

The original formula can be turned into.

a/(a-1)÷a=1/(a-1);

Bring in a worth to:

Original = 1 2 = 2 2

[2a/(a-1)+a/(1-a)]÷a=[2a/(a-1)-a/(a-1)]÷a=[(2a-a)/(a-1)]÷a=[a/(a-1)]÷a=1/（a-1)

Because a = 2 + 1 then 1 (a-1) = 1 2 under the root number

The original formula = [2 (a-1)+1 (1-a)]xa a=2 (a-1)-1 (a-1)=1 (a-1), and the result is 2 2

The answer is the root number of two. Simplify to 1 a-1, bring in and get.

A = 45 degrees, c = 60 degrees, then b = 75 degrees.

sin60-1 = (3 of the root of the half) -1

tan60-2*tan45 = (root number 3)-2 then result = 1/2.