pls check am i correct? thanks

[newuser]

Question: find the sets for all 4 graphs:
A={x€R/f(x)>3}
B={x€R/f(x)<0}
C={x€R/f(x)>0}
D={x€R/f(x)<=3}
E={x€R/f(x)>=-3}
Answers:- For all 4 graphs respectively
Range of A= NULL ;(3,INFINITY) ; (3,INFINITY) ;(3,INFINITY)
Range of B= -(infinity,0) ; (6,0) ; (-infinity,0) ; (-infinity,0)
Range of C= NULL; (0,INFINITY) ; (0,INFINITY); (0,INFINITY)
Range of D= (-INFINITY,0); (-6,3] ; (-INFINITY,-4]U[1,3] ; (-INFINITY,-4)U[-2,3]
Range of E= [-3,0) ; [-3, INFINITY) ; [1,INFINITY) ; [-2,INFINITY)

 

[mmm4444bot]

A = {x€R | f(x) > 3}

Range of A= NULL ;(3,INFINITY) ; (3,INFINITY) ;(3,INFINITY)

If I understand correctly, in question (A) you are for each graph supposed to state the sub-domain corresponding to the range (3,∞).

In other words, I'm thinking that they want you to report the set of x-values where the graph lies above the line y = 3.

Your answer "null" makes sense for the graph in the upper-left because the graph doesn't even go above the x-axis. There are no values of x for which f(x) is greater than 3.

For the remaining three graphs, you gave this answer: (3,∞). In other words, you're saying that whenever x is greater than 3 then y is also greater than 3. That's clearly wrong, on each of those three graphs.

So, either I'm not understanding the question OR you're not. Can you explain in your own words what the question means to you?

 

[newuser]

If I understand correctly, in question (A) you are for each graph supposed to state the sub-domain corresponding to the range (3,∞).

In other words, I'm thinking that they want you to report the set of x-values where the graph lies above the line y = 3.

Your answer "null" makes sense for the graph in the upper-left because the graph doesn't even go above the x-axis. There are no values of x for which f(x) is greater than 3.

For the remaining three graphs, you gave this answer: (3,∞). In other words, you're saying that whenever x is greater than 3 then y is also greater than 3. That's clearly wrong, on each of those three graphs.

So, either I'm not understanding the question OR you're not. Can you explain in your own words what the question means to you?

Yeah u r right. I did mistake. I think for A answer for all graphs is null ; [1,2)U(2,6] ; [2,3)U(3,infinity) ; (-infinity,-5]U[3,infinity) respectively.
Am I correct now?
Pls tell me so that I can practice others also.