How do you find the domain and range of 1/(3t+12)13t+12?

1 Answer
May 22, 2018

"domain "(-oo,-4)uu(-4,oo)domain (,4)(4,)
"range "(-oo,0)uu(0,oo)range (,0)(0,)

Explanation:

"let " y=1/(3t+12)let y=13t+12

"the denominator cannot be zero as this would make y"the denominator cannot be zero as this would make y
"undefined. Equating the denominator to zero and solving"undefined. Equating the denominator to zero and solving
"gives the value that t cannot be"gives the value that t cannot be

"solve "3t+12=0rArrt=-4larrcolor(red)"excluded value"solve 3t+12=0t=4excluded value

rArr"domain "(-oo,-4)uu(-4,oo)domain (,4)(4,)

"rearrange making t the subject"rearrange making t the subject

y(3t+12)=1y(3t+12)=1

rArr3ty+12y=13ty+12y=1

rArr3ty=1-12y3ty=112y

rArrt=(1-12y)/(3y)t=112y3y

"solve "3y=0rArry=0larrcolor(red)"excluded value"solve 3y=0y=0excluded value

rArr"range "(-oo,0)uu(0,oo)range (,0)(0,)
graph{1/(3x+12) [-10, 10, -5, 5]}