How are the graphs #f(x)=x^3# and #g(x)=0.75(x+1)^3# related?

2 Answers
Jul 4, 2017

The graph of #g(x)# can be described as a transformation of the graph of #f(x)#.

Explanation:

First, take a look at the graph of #f(x)#.
graph{x^3 [-10, 10, -5, 5]}

Now look at the graph of #g(x)#.
graph{0.75(x+1)^3 [-10, 10, -5, 5]}

The graph of #f(x)# is vertically shrunk by a factor of #0.75# and translated left 1 unit to obtain the graph of #g(x)#.

Jul 4, 2017

See below

Explanation:

#f(x)# is what we call the parent function. Let's see what #x^3# looks like:

graph{x^3 [-10, 10, -5, 5]}

Now let's see what #(x+1)^3# looks like:

graph{(x+1)^3 [-10, 10, -5, 5]}

You should see that it's just a shifted version of the parent function. In this case, it's a horizontal shift #1# unit to the left.

Now, let's see what the constant in the function does. Since it's hard to see what's going on if we use #0.75#, let's graph another function that will tell us what a constant THAT is LESS THAN #1# does. Let's look at #0.1(x+1)^3#

graph{0.1(x+1)^3 [-10, 10, -5, 5]}

You should see that the constant is the #y#-intercept - the value when it crosses the #x# axis.