Question

Bài 3: Tìm giao các tập hợp sau:

\(a,\left(-\infty;\dfrac{1}{3}\right)\cap\left(\dfrac{1}{4};+\infty\right)\\ b,\left(-\dfrac{11}{2};7\right)\cap\left(-2;\dfrac{27}{2}\right)\\ c,\left(0;12\right)\cap[5;+\infty)\\ d,R\cap[-1;1)\)

 

Answer 1

\(\left(-\infty;\dfrac{1}{3}\right)\cap\left(\dfrac{1}{4};+\infty\right)=\left(\dfrac{1}{4};\dfrac{1}{3}\right)\)

\(\left(-\dfrac{11}{2};7\right)\cap\left(-2;\dfrac{27}{2}\right)=\left(-2;7\right)\)

\(\left(0;12\right)\cap[5;+\infty)=[5;12)\)

\(R\cap\left[-1;1\right]=\left[-1;1\right]\)

Answer 2