Suppose that the functions [tex]\( q \)[/tex] and [tex]\( r \)[/tex] are defined as follows.

[tex]\[
\begin{array}{l}
q(x) = 2x - 2 \\
r(x) = -x^2 + 1
\end{array}
\][/tex]

Find the following.

[tex]\[
\begin{array}{l}
(r \circ q)(-1) = \\
(q \circ r)(-1) =
\end{array}
\][/tex]



Answer :

Sure, let's evaluate the compositions of the functions [tex]\( q(x) \)[/tex] and [tex]\( r(x) \)[/tex] at [tex]\( x = -1 \)[/tex] step-by-step.

First, we need to recall the definitions of the functions:
[tex]\[ q(x) = 2x - 2 \][/tex]
[tex]\[ r(x) = -x^2 + 1 \][/tex]

### Step 1: Finding [tex]\((r \circ q)(-1)\)[/tex]

The notation [tex]\((r \circ q)(-1)\)[/tex] represents the composition of [tex]\( r \)[/tex] and [tex]\( q \)[/tex], evaluated at [tex]\( x = -1 \)[/tex]. This means we first apply [tex]\( q \)[/tex] to [tex]\( -1 \)[/tex] and then apply [tex]\( r \)[/tex] to the result of [tex]\( q(-1) \)[/tex].

1. Calculate [tex]\( q(-1) \)[/tex]:
[tex]\[ q(-1) = 2(-1) - 2 = -2 - 2 = -4 \][/tex]

2. Substitute [tex]\( q(-1) \)[/tex] into [tex]\( r \)[/tex]:
[tex]\[ r(q(-1)) = r(-4) \][/tex]

3. Calculate [tex]\( r(-4) \)[/tex]:
[tex]\[ r(-4) = -(-4)^2 + 1 = -(16) + 1 = -15 \][/tex]

Therefore,
[tex]\[ (r \circ q)(-1) = -15 \][/tex]

### Step 2: Finding [tex]\((q \circ r)(-1)\)[/tex]

The notation [tex]\((q \circ r)(-1)\)[/tex] represents the composition of [tex]\( q \)[/tex] and [tex]\( r \)[/tex], evaluated at [tex]\( x = -1 \)[/tex]. This means we first apply [tex]\( r \)[/tex] to [tex]\( -1 \)[/tex] and then apply [tex]\( q \)[/tex] to the result of [tex]\( r(-1) \)[/tex].

1. Calculate [tex]\( r(-1) \)[/tex]:
[tex]\[ r(-1) = -(-1)^2 + 1 = -1 + 1 = 0 \][/tex]

2. Substitute [tex]\( r(-1) \)[/tex] into [tex]\( q \)[/tex]:
[tex]\[ q(r(-1)) = q(0) \][/tex]

3. Calculate [tex]\( q(0) \)[/tex]:
[tex]\[ q(0) = 2(0) - 2 = 0 - 2 = -2 \][/tex]

Therefore,
[tex]\[ (q \circ r)(-1) = -2 \][/tex]

### Final Answers:
[tex]\[ (r \circ q)(-1) = -15 \][/tex]
[tex]\[ (q \circ r)(-1) = -2 \][/tex]