![](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>)
Whether the radius and area of a circle are in direct proportion; whether the side length and perimeter of a square are in direct proportion;
Is the radius of a circle proportional to its area
No, because the ratio of area to radius is (the product of circumference and radius). If the radius changes, the area also changes, but their ratio also changes. Therefore, although the area and radius of a circle are two related quantities, the ratio is not necessarily, The circumference of a circle is in direct proportion to its radius and diameter. Nowadays, it is easy for students to regard the two related quantities as being in direct proportion. In fact, a positive proportion must have two conditions at the same time, that is, a certain ratio in the case of correlation
Is the side length of a square proportional to its perimeter
It's in direct proportion
Perimeter = 4 * side length
RELATED INFORMATIONS
- 1. Given that a, x1, X2 and B are equal difference sequence, a, Y1, Y2 and B are equal ratio sequence, find (x1 + x2) / (y1y2) Such as the title The answer is (a + b) / (AB)?
- 2. A rectangle is 80 cm long. Cut out the largest square. Find the perimeter of the remaining figure
- 3. Given that the average of (x1, X2, X3. Xn) is a, what is the average of (3x1 + 2,3x2 + 2.3xn + 2)?
- 4. The teacher's kitchen is 30 decimeters long and 24 decimeters wide Would you please help me to think about it, how many decimeters of square tiles are needed to make it neat and fast?
- 5. The definite integral ln (x + (a ^ 2 + x ^ 2) ^ (1 / 2)) DX ranges from 0 to a
- 6. Cut the largest circle with a rectangular piece of paper 10 cm long and 8 cm wide, The radius of this circle is () cm, the perimeter is (), and the area is ()
- 7. Given the function f (x) = 2cos (π 3 − x2) (1) find the monotone increasing interval of F (x); & nbsp; (2) find the maximum and minimum of F (x) if x ∈ [- π, π]
- 8. It is proved that f (x) = - 1 / X-1 is an increasing function on (- OO, 0)
- 9. This problem proves that the function f (x) = the square of X + 1 is a function on (0, + OO) + OO is positive infinity
- 10. The odd function y = f (x) defined on R, given that y = f (x) has three zeros in the interval (0, + ∞), then the number of zeros of function y = f (x) on R is () A. 5B. 6C. 7D. 8
- 11. Find the limit of LIM [sin (x ^ 2-1)] / (x-1) x tending to 1
- 12. Find the proof limit LIM (x, y) - > (0,0) (x ^ 2 * sin ^ 2Y) / x ^ 2 + 9y ^ 2 = 0 If the problem is solved, prove that the limit = 0
- 13. The limit LIM (x ^ 2Y ^ 2) / x ^ 2 + y ^ 2 + (X-Y) ^ 2 (x, y) tends to 0
- 14. Find the limit LIM (x, y) → (0,0) x ^ 2Y ^ 2 / (x ^ 2 + y ^ 2) ^ (3 / 2) With the pinch theorem, why can't we use x ^ 2 + y ^ 2 > 2XY
- 15. Lim x ^ 2Y ^ 2 / x ^ 2Y ^ 2 + (X-Y) ^ 2 (x, y) - (0,0) limit Does not exist. Let y = KX, x ^ 2Y ^ 2 / (x ^ 2Y ^ 2 + (X-Y) ^ 2) = k ^ 2x ^ 4 / (k ^ 2x ^ 4 + (1-k) ^ 2x ^ 2) When k = 1, the limit is 1 When k is not equal to 1, the limit is 0 or infinite Do not understand the above when k is not equal to 1, how to find the limit? Distant friends
- 16. How to find the limit of LIM x ^ 2Y ^ 2 / x ^ 2Y ^ 2 + (X-Y) ^ 2 lim x^2y^2/x^2y^2+(x-y)^2 (x,y)-(0,0) How to find the limit
- 17. When x tends to ∞, Lim √ (X & # 178; + 1) - √ (X & # 178; - 1) =?
- 18. Find the limit, LIM (x tends to 0) [1-cos (1-cosx)] / X & # 178; (arcsinx) &# 178;, a problem, kneel down for a master!
- 19. lim x²e^1/x²
- 20. High number, find the limit LIM (x tends to 0) INX / x =?