A function [tex]\( f(x) \)[/tex] is defined by [tex]\( f(x) = 2x^2 + 7 \)[/tex]. What is the value of [tex]\( 2f(x) - 3 \)[/tex]?



Answer :

To find the value of [tex]\( 2 f(x) - 3 \)[/tex] given the function [tex]\( f(x) = 2x^2 + 7 \)[/tex], let's follow the steps carefully:

1. Define the function [tex]\( f(x) \)[/tex]:
[tex]\[ f(x) = 2x^2 + 7 \][/tex]

2. Evaluate [tex]\( f(0) \)[/tex]:
[tex]\[ f(0) = 2(0)^2 + 7 = 0 + 7 = 7 \][/tex]

3. Find the expression [tex]\( 2 f(x) - 3 \)[/tex]:
[tex]\[ 2 f(x) - 3 = 2 (2x^2 + 7) - 3 \][/tex]

4. Simplify the expression inside the parentheses:
[tex]\[ 2 (2x^2 + 7) = 2 \cdot 2x^2 + 2 \cdot 7 = 4x^2 + 14 \][/tex]

5. Combine like terms:
[tex]\[ 2 f(x) - 3 = 4x^2 + 14 - 3 = 4x^2 + 11 \][/tex]

6. To find the specific value at [tex]\( x = 0 \)[/tex], substitute [tex]\( x = 0 \)[/tex] into the simplified expression:
[tex]\[ 4 (0)^2 + 11 = 0 + 11 = 11 \][/tex]

Therefore, the value of [tex]\( 2 f(x) - 3 \)[/tex] when [tex]\( x = 0 \)[/tex] is [tex]\( 11 \)[/tex].

To summarize:

- [tex]\( f(0) \)[/tex] is [tex]\( 7 \)[/tex]
- [tex]\( 2 f(0) - 3 \)[/tex] is [tex]\( 11 \)[/tex]

So, the final answer is:

[tex]\[ 2 f(0) - 3 = 11 \][/tex]