![](data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" viewBox="0 0 72 71" width="72"></svg>)
Let d be the square of the circle x + the area of the bungalow of Y, then the double integral 2dxdy =? The answer is 18pi~
The area of ∫ ∫ 2dxdy = 2 * D
If the answer is 18 PI, then D is the square of the circle x + the square of y = 9
High number surface integral: calculate ∫ (x + y) e ^ (x ^ 2 + y ^ 2) ds, where l is the fan-shaped boundary bounded by circular arc y = √ (a ^ 2-x ^) and straight line y = x and y = - X
L is parameterized by y = √ (A & # 178; - X & # 178;) and y = x and y = - X: T: - π / 4 → π / 4x = acost, y = asintdx = - asintdt, Dy = acostdtds = ADT ∫ L (x + y) e ^ (X & # 178; + Y & # 178;) ds = ∫ (- π / 4, π / 4) (acost + asint) e
Advanced number problem: y ^ 2F (x) + XF (y) = x ^ 2 (^ for square), f (x) differentiable, find dy
Differential on both sides:
f(x)×2ydy＋y^2×f'(x)dx＋f(y)dx＋xf'(y)dy＝2xdx
dy＝[2x－f(y)－f'(x)y^2]dx/[2yf(x)＋xf'(y)]
Using the law of lobita to get the derivative LIM (x → pi / 2-0): (TaNx) ^ (2x PI) pi = 3.1415926
LIM (x → π / 2-0) (TaNx) ^ (2x - π) = e ^ LIM (x → π / 2-0) (2x - π) ln (TaNx) = e ^ LIM (x → π / 2-0) ln (TaNx) / [1 / (2x - π)] ∞ / ∞ type, using the law of Robida = e ^ LIM (x → π / 2-0) 1 / (TaNx) * sec ^ 2x / [- 2 / (2x - π) ^ 2] = e ^ LIM (x → π / 2-0) - (2x - π)
RELATED INFORMATIONS
- 1. Let l be the circle x2 + y2 = 4, and the root of the curve integral (x2 + Y2) DS is equal to?
- 2. Q is the moving point on the circle x ^ 2 + y ^ 2 = 4, and there is another point a (radical 3,0). The intersection radius OQ of the vertical bisector of the line segment AQ is at p. when the Q point moves on the circle, we can find Q is the moving point on the circle x ^ 2 + y ^ 2 = 4, and there is another point a (radical 3,0). The intersection radius OQ of the vertical bisector of the line segment AQ is p. when Q moves on the circle, the trajectory of P is obtained
- 3. Given the circle C: (x + 1) 2 + y2 = 25 and point a (1, 0), q is a point on the circle, and the vertical bisector of AQ intersects CQ at m, then the trajectory equation of point m is______ ．
- 4. What is the projection curve equation of the space curve equations z = x ^ 2 + y ^ 2, z = 2 - (x ^ 2 + y ^ 2) on the xoy plane and how to calculate it, Tell me about the curve equation, such as on that plane, how to spin the segment around which axis, OK,
- 5. Surface integral, Gauss formula Using Gauss formula to divide the area of an upper hemisphere, add a bottom surface to make it a closed surface At this time, the problem arises. After dividing the closed surface, do you want to subtract the integral of the auxiliary surface or add the integral of the auxiliary surface? One book is added and the other is subtracted. I'm confused Is there any difference between the outer side integral and the upper side integral?
- 6. Calculate the surface integral ∫ ∫ ∑ Z ^ 2 DS, where ∑ is the part of cylinder x ^ 2 + y ^ 2 = 4 between 0 ≤ Z ≤ 6
- 7. It is known that the focal coordinates of two parabolas are (2,0), (0,2), and the standard equations of them are obtained
- 8. The known number of teeth Z1 = 23 Z2 = 45 modulus M = 4 pitch circle pressure angle 20 degree pitch circle pressure angle 23 degree Find the pitch circle diameter D1 D2 base circle diameter db1 pitch circle diameter D3 D4 actual center distance a
- 9. Involute cylindrical gear transmission module M = 50 mm, pressure angle a = 20, transmission ratio i = 2.5, the number of pinion teeth is 20, the center distance of pinion indexing circle diameter gear circle
- 10. In this case, if we want to increase the same amount of output, we should increase the input of variable production factors. Why increase the input?
- 11. As shown in the figure, the line y = 2x intersects the hyperbola y = 2, X at point A. after translating the line y = 2x downward by 6 units, it intersects the x-axis at point C, then the coordinate of point C is
- 12. If the curve L is x ^ 2 + y ^ 2 = 9, then the curve integral ∫ (x ^ 2 + y ^ 2) ds =? I figured it out to be 54 π. Why don't I have that answer
- 13. ∫ (2,1) root sign (4-x ^ 2) / x ^ 2 DX PS: the root sign is (4-x ^ 2) and the denominator is x ^ 2 I can't do it. Thank you for your advice
- 14. Proof of curvature of plane curve K | DX / DS | = | D (dy / DS) / DS| S is the length of an arc from a (a, f (a)) to P (x, y) on the curve y = f (x), K is the curvature of the curve at point P
- 15. What are DS and s in curve integral? What do they mean? What's the big change, the small change, the constant change, the approximate sum and the limit?
- 16. The operation of quadratic equation: 1, 2x-y-1 equal to 0 and x ^ 2-y ^ 2 = 0, 2, 2x-y-1 greater than 0 and x ^ 2-y ^ 2 less than 0
- 17. As shown in the figure, point a on the circle moves in a circular motion at a constant speed in a counter clockwise direction. It is known that point a turns around the angle of θ (0 ＜ θ ＜ π) in 1 minute, reaches the third quadrant in 2 minutes, and returns to its original position in 14 minutes to calculate θ
- 18. As shown in the figure below, point a on the circumference moves in a circular motion at a constant speed in a counter clockwise direction. It is known that point a turns θ (0
- 19. The necessary and sufficient condition for the curve of equation x ^ 2 + y ^ 2-3x-2y + k = 0 to pass through the origin is K=
- 20. It is known that a and B are two fixed points, and the distance ratio from the moving point m to a and B is constant λ