It is known that the minimum positive period of the function f (x) = 2 times of the root sign sinwxcos (Wx + Pie / 4) + 1 / 2 is 2 pie (W > 0) (1) (2) let the opposite sides of the internal angles a, B and C of the triangle ABC be a, B and C respectively. If f (a) = root 2 / 2, B = 1 and the area of the triangle ABC is 1, then a

It is known that the minimum positive period of the function f (x) = 2 times of the root sign sinwxcos (Wx + Pie / 4) + 1 / 2 is 2 pie (W > 0) (1) (2) let the opposite sides of the internal angles a, B and C of the triangle ABC be a, B and C respectively. If f (a) = root 2 / 2, B = 1 and the area of the triangle ABC is 1, then a

① Because f (x) = two times of the radical sinwxcos (Wx + π / 4) + 1 / 2 = two times of the radical sinwx [coswx × cos π / 4-sinwx × sin π / 4] + 1 / 2
=Sinwx × coswx - (sinwx) ^ 2 + 1 / 2 = 1 / 2sin2wx - (1-cos2wx) / 2 + 1 / 2 = root 2 / 2Sin (2wx + π / 4)
The minimum positive period of F (x) is 2 π and W > 0, so t = 2 π / w = 2 π, so w = 1 / 2
② Because f (a) = radical 2 / 2, that is, radical 2 / 2Sin (a + π / 4) = radical 2 / 2, so a = π / 4, and s △ ABC = 1 / 2 × B × C ×
Sina = 1 and B = 1, so C = 2 times the root 2, and because cosa = (b ^ 2 + C ^ 2-A ^ 2) / 2BC, a = root 5 is brought in

If the common ratio of an is - 1 / 2, the value of LIM ((A2 + A4 +... A2N) / (a1 + A2 +... + an)) is

-1

Write a quadratic polynomial with only the letter M, its quadratic coefficient is 4, the coefficient of the first term is - 3, the constant term and the coefficient of the first term are opposite to each other, this polynomial is

4m^2-3m+3

A barrel of oil weighs 11.45kg, half of which weighs 5.95kg. How many kg is the barrel?

(11.45-5.95)*2=11

Finding the derivative of y = x ^ 2 * sin (1 / x) (x is not equal to 0)
How to do it. I get 2 * sin (1 / x) - x ^ 2 * cos (1 / x)

2*sin(1/x)-x^2*cos(1/x)*1/(x^2)

How to solve the equation x * 5 + 4 = x * 7 + 24

The term is shifted to 2 * x = 20, so x = 10

The inner diameter of the tap water outlet is 2 cm. Turn on the tap to discharge water. The water flow rate is 8 cm per second. How many liters of water can be discharged?

5 minutes = 300 seconds
Inner radius of water outlet = 2 △ 2 = 1 (CM)
Volume of water discharged in 5 minutes
=3.14×1×1×8×300
=7536 (cm3)
=7.536 (L)

Let x → 0, etanx ex and xn be infinitesimals of the same order, then n is ()
A. 1B. 2C. 3D. 4

∵ TaNx = x + 13x3 + O (x3) & nbsp; etanx-x-1 ～ tanx-x ∵ etanx − ex = ex (etanx − x − 1) = 13x3 + O (x3) ∵ etanx ex and X3 are non equivalent infinitesimals of the same order ∵ n = 3, so C

3 / 4 + (5 / 6-3 / 4) = 5 / 6 + (1 / 6 + 5 / 9) + 2 / 9 = 1 / 6 + 5 / 7 + 5 / 6 + 2 / 7=
1 - (5 / 12-1 / 4)=
7 / 8 - (5 / 6-1 / 8)=
If you can do it, do it
Out of form calculation

3 / 4 + (5 / 6-3 / 4)
=3 / 4 + 5 / 6-3 / 4
=3 / 4-3 / 4 + 5 / 6
=5 out of 6
5 / 6 + (1 / 6 + 5 / 9) + 2 / 9
=5 / 6 + 1 / 6 + 5 / 9 + 2 / 6
=1 + 7 / 9
=1 and 7 / 9
1 / 6 + 5 / 7 + 5 / 6 + 2 / 7
=1 / 6 + 5 / 6 + 5 / 7 + 2 / 7
=1+1
=2
3 / 5 + 8 / 15 + 7 / 10
=18 out of 30 + 16 out of 30 + 21 out of 30
=30 (18 + 16 + 21)
=45 out of 30
=3 / 2
=One and one in two
1 - (5 / 12-1 / 4)
=1 - (5 / 12-3 / 12)
=1-2 / 12
=1-1 / 6
=5 out of 6
7 / 8 - (5 / 6-1 / 8)
=7 / 8-5 / 6 + 1 / 8
=7 / 8 + 1 / 8-5 / 6
=1-5 / 6
=One in six

1.3x-y + 2 (y ^ - x ^) - 2 (- x ^ + 2Y ^), choose a group of numbers you like instead of the values of X and y
2. Try to compare the size of rational number a and 1 / a (a is not equal to 0)
3x-y + 2 (2Y ^ - x ^) - 2 (- x ^ + 2Y ^), choose a group of numbers you like instead of the values of X and y. Wrong, two less.
2Y ^ is the quadratic power of Y, and the others are all quadratic.

Because a is not zero, it has only positive and negative numbers
When a is a positive number and a negative fraction, a is greater than 1 / A
When a is a negative number and a positive fraction, a is less than 1 / A
When a is 1, a is equal to 1 / A