Core Connections Integrated II, 2015
CC
Core Connections Integrated II, 2015 View details
Chapter Closure

Exercise 147 Page 537

a We are given the following function.

f(x) = 2x^2

Using this function we want to find the expression g(x) = f(x)+2. To do this, we will add 2 to the given function and simplify.
f(x)=2x^2
f(x)+ 2=2x^2+ 2
f(x)+2=2x^2+2

Therefore, the transformed function g(x) is given by the following formula. g(x) = 2x^2+2 Vertical translations occur when we add or subtract a value from the output of a function. We can observe it more clearly in the table below.

Vertical Translations
Translation up k units, k>0 y=f(x)+ k Translation down k units, k>0 y=f(x)- k

Therefore, we can describe our transformation as vertical translation 2 units up. It means that the graph of the given function was shifted 2 units up.

b Like in Part A, we are given the following function.

f(x) = 2x^2

Using it, we want to find the expression h(x) = 2 * f(x). To do this, we will multiply the given function by 2 and simplify.
f(x)=2x^2
2 * f(x)= 2(2x^2)
2 * f(x)=4x^2

Therefore, the transformed function h(x) is given by the following formula. h(x) = 4x^2 We can look at the following table to determine how we can describe out transformation.

Vertical Stretch or Shrink
Vertical stretch, a>1 y=af(x) Vertical shrink, 0

We can describe our transformation as vertical stretch by a factor of 2.

c Like in Parts A and B, we are given the following function.

f(x) = 2x^2

Using this function, we want to find the expression j(x) = f( x+2). To do this, we need to substitute x+2 for x in each instance of the x-variable.
f(x)=2x^2
f( x+2)=2( x+2)^2

Therefore, the transformed function f(x) is given by the following formula. f(x) = 2(x+2)^2 Horizontal translations occur when we add or subtract a value from the input of a function. We can observe it more clearly in the table below.

Horizontal Translations
Translation right h units, h>0 y=f(x- h) Translation left h units, h>0 y=f(x+ h)

We can describe this transformation as horizontal translation 2 units left. It means that the graph of the given function was shifted 2 units left.

d Like in previous parts, we are given the following function.

f(x) = 2x^2

Using the function f(x), we want to find the expression k(x)=f( 2x). To do this, we need to substitute 2x for x in each instance of the x-variable and simplify.
f(x)=2x^2
f( 2x)=2( 2x)^2
f(2x)=2(2)^2x^2
f(2x)=2(4)x^2
f(2x)=8x^2

Therefore, the transformed function k(x) is given by the following formula. k(x) = 8x^2 Let's name our transformation using the table below.

Horizontal Stretch or Shrink
Horizontal stretch, 0 Horizontal shrink, b>1 y=f(bx)

We can describe this transformation as horizontal stretch by a factor of 2. However, we can look at the resulting function in different way — as a vertically stretched function f(x). k(x) = 8x^2 = 4(2x^2) ⇕ k(x) = 4 f(x) Hence, using the table below, we can also say that this transformation is a wertical stretch by factor of 4.

Vertical Stretch or Shrink
Vertical stretch, a>1 y=af(x) Vertical shrink, 0