How do you graph y=1/4sqrt(x-1)+2y=14x1+2, compare to the parent graph, and state the domain and range?

1 Answer
Jan 4, 2018

D_f=[1,+oo)Df=[1,+) , R_f=[2,+oo)Rf=[2,+)

Explanation:

graph{sqrt(x-1)/4+2 [-10, 10, -5, 5]}

The graph is sqrtxx shifted 11 to the right and what comes out of that shifted 22 times upwards.

D_fDf=={AAx{xinRR: x-1>=0} = [1,+oo)

I will find the range using Monotony and continuity.

f(x)=1/4sqrt(x-1)+2 ,
x>=1

f'(x)=1/4*((x-1)')/(2sqrt(x-1)) =

1/(8sqrt(x-1)) >0 , xin(1,+oo)

Therefore f is strictly increasing uarr in [1,+oo)

  • R_f=f(D_f)=f([1,+oo))=[f(1),lim_(xrarr+oo)f(x)) =

= [2,+oo)

because lim_(xrarr+oo)f(x)=lim_(xrarr+oo)(sqrt(x-1)/4+2) = +oo

NOTE: lim_(xrarr+oo)(x-1)=+oo therefore, lim_(xrarr+oo)sqrt(x-1)=+oo