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The functional relationship between price f (T) and time t of a commodity in recent 30 days is f (T) = t + 10 (0
(t+10)*(35-t)≧450
5≦t≦20
In a month (30 days), the functional relationship between the selling price P (yuan) and the time t (day) is: P = t + 10 (1 less than or equal to t less than, etc
Within one month (30 days), the functional relationship between price P (yuan) and time t (day) is: P = t + 10 (1 ≤ t ≤ 24. T)
Within one month (30 days) of a commodity, the functional relationship between price P (yuan) and time t (day) is: P = t + 10 (1 less than or equal to t less than)
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1. Try to compare the size of 0.16-3 / 4, 0.5-3 / 2, 6.253/8
2. Known (0.71.3) M0 (for analysis)
3. If at least one of the intersections of the image of the function y = MX2 + (M-3) x + 1 and the X axis is on the right side of the origin, try to find the value range of M
Thank you!
1、-1
1. Decreasing function and monotone decreasing interval
Given that f (x) = x ^ 2-2 (1-A) x + 2 is a decreasing function (monotone decreasing interval) on (- 00,4), find the value range of real number a?
If the question condition is minus function, the answer is (- 00, - 3]
If the problem condition is monotone decreasing interval, - 3
If the decreasing function is (1)
If the monotone decreasing interval is (2), we can use (1), (2) to answer.
One way to say it is a decreasing function on (- 00,4), so he only needs to monotonically decrease on it. His monotone decreasing interval can be (- 00,5]
(- 00,6] and so on. Another monotone decreasing interval is (- 00,4). So the answer is different. The former indicates the abscissa of the axis of symmetry
Greater than or equal to 4 indicates that the axis of symmetry is equal to 4
Use the sum (difference) angle formula to find the values of the following trigonometric functions
1 cos（（-61/12）π）=____________
2 tan((35π)/12)=____________________
1、
Original formula = cos (- 3 * π + 11 π / 12)
=cos(11π/12)
=cos(π/4+2π/3)
=cosπ/4cos2π/3-sinπ/4sin2π/3
=-(√6+√2)/4
2、
The original formula = Tan (3 π - π / 12)
=tan(-π/12)
=tan(π/4-π/3)
=(tanπ/4-tanπ/3)/(1+tanπ/4tanπ/3)
=-2+√3
1. If functions f (x) and G (x) are increasing functions in interval D, is function f (x) = f (x) + G (x) increasing function in interval D? If yes, please prove it.
2. For any two values x1, X2 (x1 is not equal to x2) of function f (x) on an interval D in the domain of definition, if f (x1) - f (x2) / x1-x2 > 0, is the function monotone in interval D? f(x1)-f(x2)/x1-x2
1. Any two values x1, x, 2 of function f (x) on an interval D in the domain of definition, let x2 > x1
Because the functions f (x) and G (x) are increasing functions in the interval D
So f (x2) - f (x1) > 0, G (x2) - G (x1) > 0
Then f (x2) - f (x1) = [f (x2) + G (x2)] - [f (x1) + G (x1)]
= f(x2)-f(x1)+ g(x2)-g(x1)>0
So f (x) is an increasing function in the interval D
2.f(x1)-f(x2)/x1-x2 >0
If X1 > X2, then f (x2) - f (x1) > 0, that is, f (x2) > F (x1) increasing function
If x1
If a > 0, b > 0, and a + B = C, then RC ^ R,
Think about this topic as follows:
Let a / C = x, B / C = y, then x + y = 1, then we can know: 0C ^ R
If you think I don't understand, you can continue to ask me~
Given a > 0, b > 0, it is proved that 2 (√ a + √ b) ≤ a + B + 2
(a+b+2)-[2(√a+√b)]
=a+b+2-2√a-2√b
=a-2√a+1+b-2√b+1
=(a-2√a+1)+(b-2√b+1)
=(√a-1)²+(√b-1)²≥0
(add two numbers not less than 0, the result is not less than 0)
(a+b+2)-[2(√a+√b)]≥0
SO 2 (√ a + b) ≤ a + B + 2
The equal sign is obtained when a = b = 1
Proof: a (a-b) + B (B-C) - C (A-C) = 0
Proof question:
It is known that a (a-b) + B (B-C) - C (A-C) = 0
Verification: a = b = C
A * A-A * B + b * B-B * C-C * a + C * C = 0
Multiply two sides by two
a*a-2ab+b*b+b*b-2bc+c*c+a*a-2ac+c*c=0
(a-b) 2 + (B-C) 2 + (A-C) 2 = 0 (2 outside brackets is quadratic)
It is known that if and only if a = b = C or a = b = C = 0
I wish you success in your study
Let a = {a, B, C} and B = {0, 1}. How many mappings are there from a to B? And let them be expressed separately
There are eight maps from a to B. PS: mapping from a to B, we need to find the element in a
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