How do you find the domain and range of #y=4absx#?

1 Answer
Apr 18, 2017

#x inRR#
#y in[0,+oo)#

Explanation:

#"making a 'quick' sketch of the function will help"#

#"choose values of x and calculate y"#

#color(red)(x=0)toy=4|0|=0to(0,0)#

#color(red)(x=1)toy=4|1|=4to(1,4)#

#color(red)(x=2)toy=4|2|=8to(2,8)#

#color(red)(x=-1)toy=4|-1|=4to(-1,4)#

#color(red)(x=-2)toy=4|-2|to(-2,8)#

#"plotting these points gives"#
graph{4|x| [-11.25, 11.24, -5.62, 5.635]}

#"from the graph we can see domain/range"#

#"domain is " x inRR#

#"range is " [0,+oo)#