How to translate the composition of unit 3 section a 3A?

How to translate the composition of unit 3 section a 3A?

Subject: Jack sender: Ted dear Jack: I had a very unusual experience on Sunday. I was walking along the street at about 10 a.m. when a UFO landed right in front of me. You can imagine how strange it is! An alien came out and walked down the center street. I followed it to see if it was going to

Translation of English 35 pages 2B

Today’s story is about Zhu Hui,a student from Shenzhen.He ’s now studying in the United States.He ’s living with an American family in New York.Today is the Dragon Boat Festival.It ’s 9:00 am.and Zhu ...

It is known that positive real numbers a, B and C are the three sides of △ ABC respectively, and a ^ 4-b ^ 4-C ^ 4 + 2B & sup2; C & sup2; = 0. Try to judge the shape of △ ABC

The two triangles have the same area. One of the bottom edges of the first triangle is 7.2 cm long, and the height of the bottom edge is 4.2 cm. The other triangle is 5.4 cm long. What is the corresponding height of the bottom edge?

What is the area of a triangle
7.2 × 4.2 △ 2 = 15.12 (cm2)
The height corresponding to the bottom edge is
15.12 × 2 △ 5.4 = 5.6 (CM)

Log bottom (x ^ 2 + 4) + log bottom (y ^ 2 + 1) = log bottom 5 + log bottom (2xy-1), a > 0 and a ≠ 1, log bottom 8 (Y / x)
Such as the title

The original equation can be sorted as: x ^ 2Y ^ 2-10xy + x ^ 2 + 4Y ^ 2 + 9 = 0 (x ^ 2Y ^ 2-6xy + 9) + (x ^ 2 + 4Y ^ 2-4xy) = 0 (xy-3) ^ 2 + (x-2y) ^ 2 = 0xy = 3, x-2y = 0, Y / x = 1 / 2log8 (Y / x) = log8 (1 / 2) = 1 / 3

To make a square bottomless water tank with a volume of 256l, what's its height and material saving?

Let the height of the tank be x and the length of the bottom edge be a, then a 2x = 256 and its surface area s = 4ax + a 2 = 1024a + a 2 = 512a + 512a + a 2 ≥ 33512a × 512a × a 2 = 3 × 26 = 192. If and only if a = 8, that is, H ﹥ 4, s gets the minimum

It is known that the triangle ABC is an equilateral triangle, ab = 1, P and Q are the points on AB and AC in turn, and the segment PQ divides the area of triangle ABC into two equal parts
AP = x, PQ = y, find the functional relationship between Y and X, y = f (x)

AP=x
Because PQ bisects the area of triangle ABC,
Then (AP * AQ) / (AB * AC) = 1 / 2
Then x * AQ = 1 / 2
AQ=1/(2x)
AP=x,PQ=y
The cosine theorem is: y ^ 2 = x ^ 2 + AQ ^ 2-x * AQ = x ^ 2 + 1 / (4x ^ 2) - 1 / 2
So y = x ^ 2 + 1 / (4x ^ 2) - 1 / 2 under the root sign

The straight line intersecting parabola x ^ 2 = 4Y passing through point P (0, - 2) is at two points A.B. it is the tangent intersection of parabola at A.B. it is at M. find the locus of point M

Answer: let the straight line be y + 2 = KX, K ≠ 0, y = kx-2, and substitute it into the parabolic equation
x^2-4kx+8=0
Because there are two intersections A and B, so:
△ = 16K ^ 2-4 * 8 > 0, k > √ 2 or K

As shown in the figure, Xiaohong uses a rectangular piece of paper ABCD for origami. It is known that the width ab of the paper is 8cm and the length BC is 10cm. When Xiaohong folds, the vertex D falls at point F on the edge of BC (the crease is AE). Think about it, how long is EC at this time? Explain in the way you've learned

In RT △ ABF, ab = 8, AF = 10, ｜ BF = af2 − AB2 = 6, ｜ CF = bc-bf = 4, let CE = x, then de = EF = 8-x, in RT △ CEF, ∵ CF2 + CE2 = ef2, ∵ 42 + x2 = (8-x) 2, the solution is x = 3, that is, the length of EC 3 cm

If X1 and X2 are two real roots of the quadratic equation x2-6x-2 = 0, then the value of X1 + X2 is ()
A. -6B. -2C. 6D. 2

Therefore, the answer is: 6