Bytelearn - cat image with glassesAI tutor

Welcome to Bytelearn!

Let’s check out your problem:

已知集合 
A={x∣sqrt(x-1) <= 2}*B={y∣-y^(2)+3y > 0}, 则 
A nn B=

C_(3)
A. 8
B. 
(0.3)
C. 
(0,5]
D. 
[1,3)

11. 已知集合 A={xx12}B={yy2+3y>0} A=\{x \mid \sqrt{x-1} \leqslant 2\} \cdot B=\left\{y \mid-y^{2}+3 y>0\right\} , 则 AB= A \cap B= \newlineC3 \mathrm{C}_{3} \newlineA. 88\newlineB. (0.3) (0.3) \newlineC. (0,5] (0,5] \newlineD. [1,3) [1,3)

Full solution

Q. 11. 已知集合 A={xx12}B={yy2+3y>0} A=\{x \mid \sqrt{x-1} \leqslant 2\} \cdot B=\left\{y \mid-y^{2}+3 y>0\right\} , 则 AB= A \cap B= \newlineC3 \mathrm{C}_{3} \newlineA. 88\newlineB. (0.3) (0.3) \newlineC. (0,5] (0,5] \newlineD. [1,3) [1,3)
  1. Set A Solution: For set A, we have x12\sqrt{x-1} \leq 2. Square both sides to get rid of the square root: (x1)222(\sqrt{x-1})^2 \leq 2^2. This gives us x14x - 1 \leq 4. Add 11 to both sides: x5x \leq 5. So, A={xx5 and x>1}A = \{x | x \leq 5 \text{ and } x > 1\} because we can't take the square root of a negative number.
  2. Set B Solution: For set B, we have y2+3y>0-y^2 + 3y > 0.\newlineFactor out yy: y(y+3)>0y(-y + 3) > 0.\newlineThis gives us two critical points, y=0y = 0 and y=3y = 3.\newlineThe inequality is satisfied between these points: 0<y<30 < y < 3.\newlineSo, B={y0<y<3}B = \{y | 0 < y < 3\}.
  3. Intersection of A and B: Now let's find the intersection ABA \cap B.\newlineSince A={x1<x5}A = \{x | 1 < x \leq 5\} and B={y0<y<3}B = \{y | 0 < y < 3\}, the intersection is the set of all numbers that are both greater than 11 and less than or equal to 33.\newlineSo, AB={x1<x3}A \cap B = \{x | 1 < x \leq 3\}.
  4. Final Answer: Looking at the answer choices, we see that the correct answer is DD. [1,3)[1,3).

More problems from Solve complex trigonomentric equations