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Classified discussion questions in mathematics concentration of senior one.
Known set p = {x | 4

(1) Find the range of real number k when p crosses Q= empty set.

(2) Find the value range of real number k when p crosses q = \ q ..

note:

= \ means "not equal to"

(a), when p across Q= empty set, can be divided into the following situations.

( 1)、k+ 1 & gt; 5->; K> iv

(2)、2k- 1 & lt; 4->; k & lt(5/2)

(3) Q itself is an empty set, that is, k+1>; 2k- 1->; k & lt2

To sum up, the range of real number k is {k | k>4 or k < (5/2)}.

(2),

Suppose p crosses q = q

so 4 < = k+ 1 & lt; = 5->; 3 & lt= k & lt=4

And 4

Or q itself is an empty set, that is, k+1>; 2k- 1->; k & lt2

When p crosses q = \ q

The range of real number k is {k | k >;; =2 and k=\3}