Find the range of the function

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Homework Statement



The function f is defined by

f(x) = sqrt(7-3x) , x<=1

= 3x^2-4x+3 , x>1

(1) Find the range of f

(2) if g(x)=sqrt(7-3x) , h(x)=3x^2-4x+3 in the case where f is continuous , find the composite function hg and state its domain and range.

(3) Determine the largest set for the domain and the corresponding range such that hg is one to one.

Homework Equations





The Attempt at a Solution



(1) Range=[2,infinity)

(2) hg(x)=24-9x-4sqrt(7-3x)

domain=(- inifinity , 7/3)

range = [3 , infinity)

(3) some hints on this.
 
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You didn't get the correct range in part (2).

Try plotting hg(x). It'll help you see the answers for parts (2) and (3).
 


vela said:
You didn't get the correct range in part (2).

Try plotting hg(x). It'll help you see the answers for parts (2) and (3).

ok

got it!Thanks again Vela!
 
Last edited:
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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