Big Ideas Math Algebra 1, 2015
BI
Big Ideas Math Algebra 1, 2015 View details
1. Graphing Square Root Functions
Continue to next subchapter

Exercise 4 Page 543

Practice makes perfect
a Consider the given function.
g(x)=sqrt(x-1) Let's write a table of values for this function. Since the radicand cannot be negative, we will start with x=1.
x sqrt(x-1) g(x)=sqrt(x-1)
1 sqrt(1-1) 0
2 sqrt(2-1) 1
3 sqrt(3-1) ≈ 1.41
4 sqrt(4-1) ≈ 1.73
5 sqrt(5-1) 2

We will now plot the points and connect them with a smooth curve.

square root function

Next, we will compare this graph to the square root function.

square root function

We can see that the graph of g(x) is a translation of f(x) by one unit to the right.

b Consider the given function.
g(x)sqrt(x)-1 Let's write a table of values for this function. Since the radicand cannot be negative we will start from x=0.
x sqrt(x)-1 g(x)=sqrt(x)-1
0 sqrt(0)-1 -1
1 sqrt(1)-1 0
2 sqrt(2)-1 ≈ 0.41
3 sqrt(3)-1 ≈ 0.73
4 sqrt(4)-1 1

We will now plot the points and connect them with a smooth curve.

square root function

Next, we will compare this graph to the square root function.

square root function

We can see that the graph of g(x) is a translation of f(x) by one unit down.

c Consider the given function.
g(x)=2sqrt(x) Let's write a table of values for this function. Since the radicand cannot be negative we will start from x=0.
x 2sqrt(x) g(x)=2sqrt(x)
0 2sqrt(0) 0
1 2sqrt(1) 2
2 2sqrt(2) ≈ 2.83
3 2sqrt(3) ≈ 3.46
4 2sqrt(4) 4

We will now plot the points and connect them with a smooth curve.

square root function

Next, we will compare this graph to the square root function.

square root function

We can see that the graph of g(x) is a vertical stretch of f(x) by a factor of 2.

d Consider the given function.
g(x)=-2sqrt(x) Let's write a table of values for this function. Since the radicand cannot be negative we will start from x=0.
x -2sqrt(x) g(x)=-2sqrt(x)
0 -2sqrt(0) 0
1 -2sqrt(1) -2
2 -2sqrt(2) ≈ -2.83
3 -2sqrt(3) ≈ -3.46
4 -2sqrt(4) -4

We will now plot the points and connect them with a smooth curve.

square root function

Next, we will compare this graph to the square root function.

square root function

We can see that the graph of g(x) is a composite transformation. It is an x-axis reflection of a vertical stretch of f(x) by a factor of 2.