Matlab for solving quartic equation of one variable Help to use matlab to solve 5 * (- 0.0000003) * x ^ 4 + 4 * (0.0000308) * x ^ 3 + 3 * (- 0.00105) * x ^ 2 + 2 * 0.01209 * x-0.0000211 = 0

Matlab for solving quartic equation of one variable Help to use matlab to solve 5 * (- 0.0000003) * x ^ 4 + 4 * (0.0000308) * x ^ 3 + 3 * (- 0.00105) * x ^ 2 + 2 * 0.01209 * x-0.0000211 = 0

solve('5*(-0.0000003)*X^4+4*(0.0000308)*X^3+3*(-0.00105)*X^2+2*0.01209*X-0.000021=0','0

2.8 times 2.5 times 1.25 times 4

2.8 by 2.5 by 1.25 by 4
=0.7x(4x2.5)x(1.25x4)
=0.7x10x5
=35

A parallelogram is shown in the figure. The area of the shadow is 28 square centimeters. The area of this parallelogram is______ Square meters

28 × 2 = 56 (square centimeter) = 0.0056 (square meter); answer: the area of this parallelogram is 0.0056 square meter

1. If the image of the quadratic function y = - 3x ^ 2 + 2x + m has three intersections with the two coordinate axes, then the value range of M is
2. In △ ABC, ∠ a = 15 ° and ∠ B = 30 °, then BC=
3. The coordinate of point P is (- 2,5). If the circle with radius R is separated from X axis and intersects with y axis, the value range of R is -
4. If circle a, circle B and circle C are tangent to each other, the radius of circle a is 2, the radius of circle B is 4, ∠ BAC = 90 °, then the radius of circle C is 2

M > - 1 / 3 and M is not equal to 0;
2. The condition is not complete, only know that the two corners can not find the edge, for example, is a similar triangle
three point two

If the square of X + 6x + k is a complete square, then k = ()

If the square of X + 6x + k is a complete square, then k = (9)

The diameter of a semicircle is equal to the right side of an isosceles right triangle. The area of an isosceles right triangle is 20 square centimeters. What is the area of a semicircle?
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31.

(Meishan, 2011) as shown in the figure, the straight line y = - x + B (b > 0) and hyperbola y = KX (x > 0) intersect at two points a and B, connecting OA and ob, am ⊥ Y axis at m, BN ⊥ X axis at n; the following conclusions are obtained: ① OA = ob; ② △ AOM ≌ Δ Bon; ③ if ∠ AOB = 45 °, then s △ AOB = k; ④ when AB = 2, on-bn = 1; the number of correct conclusions is ()
A. 1B. 2C. 3D. 4

Let a (x1, Y1) and B (X2, Y2) be substituted into y = KX to obtain x1 · Y1 = x2 · y2 = k, y = − x + by = KX, and X2 BX + k = 0, then x1 · x2 = k, then x1 · Y1 = k, and X1 · Y1 = k, ｜ x2 = Y1, similarly to x2 · y2 = k, we can obtain X1 = Y2, ｜ on = OM, am = BN, ｜ ① OA = ob, ② △ AOM ≌ Δ Bon, correct; ③

How to read the sign of partial derivative?

The more common way to read it is "Pian", for example, Pian Z is better than Pian x, and it can also read "patao"

Three eighths of the bridge has been repaired. The repaired part is regarded as unit 1. The UN repaired part is regarded as unit 1

c. Unit "1"

Let F 1 (x) = x ^ 2-B, F 2 (x) = - (x + a) / F 3 (x) (a, B ∈ R), and F 2 (x) monotonically increases on (- ∞, 1) and decreases on [1,3]
Finding the relation between a and B

The solution: (1) because: the distance between the C point (1,3 / 2) F1 and F2 of the ellipse is equal to that in the definition of ellipse: 4 to 4 = 2A, then: = 2 again: ellipse C: x2 / A2 + Y2 / B2 = 1 (> b > 0), so: the standard equation of ellipse can be expressed as: χ ^ 2 / 4 + y ^ 2 / b ^ 2 =