Answer :

Sure, let's solve the problem step-by-step.

Part (a) \( g(4.2) \)

Given the function \( g(x) = \frac{x}{2} + 7 \), we need to find the value of \( g \) at \( x = 4.2 \).

1. Substitute \( x = 4.2 \) into the function \( g(x) = \frac{x}{2} + 7 \).
2. Calculate \( \frac{4.2}{2} \):
[tex]\[ \frac{4.2}{2} = 2.1 \][/tex]
3. Add 7 to this result:
[tex]\[ 2.1 + 7 = 9.1 \][/tex]

Therefore, \( g(4.2) = 9.1 \).

Part (b) \( g(-4.2) \)

Again, using the function \( g(x) = \frac{x}{2} + 7 \), we need to find the value of \( g \) at \( x = -4.2 \).

1. Substitute \( x = -4.2 \) into the function \( g(x) = \frac{x}{2} + 7 \).
2. Calculate \( \frac{-4.2}{2} \):
[tex]\[ \frac{-4.2}{2} = -2.1 \][/tex]
3. Add 7 to this result:
[tex]\[ -2.1 + 7 = 4.9 \][/tex]

Therefore, \( g(-4.2) = 4.9 \).

So, the final results are:
- \( g(4.2) = 9.1 \)
- [tex]\( g(-4.2) = 4.9 \)[/tex]