Given the functions:
[tex]\[
\begin{array}{l}
f(x) = 4x^2 + 5x - 3 \\
g(x) = 4x^3 - 3x^2 + 5
\end{array}
\][/tex]

Find [tex]\((f + g)(x)\)[/tex].



Answer :

To find \((f+g)(x)\), we need to add the two functions \(f(x)\) and \(g(x)\) together. Here's the step-by-step process to obtain \((f+g)(x)\):

Given:
[tex]\[ f(x) = 4x^2 + 5x - 3 \][/tex]
[tex]\[ g(x) = 4x^3 - 3x^2 + 5 \][/tex]

To find \((f+g)(x)\), we need to add \(f(x)\) and \(g(x)\):
[tex]\[ (f+g)(x) = f(x) + g(x) \][/tex]

Let's substitute \(f(x)\) and \(g(x)\) with their respective expressions:
[tex]\[ (f+g)(x) = (4x^2 + 5x - 3) + (4x^3 - 3x^2 + 5) \][/tex]

Now, combine like terms:

1. The \(x^3\) term:
[tex]\[ 4x^3 \][/tex]

2. The \(x^2\) terms:
[tex]\[ 4x^2 - 3x^2 = x^2 \][/tex]

3. The \(x\) term:
[tex]\[ 5x \][/tex]

4. The constant terms:
[tex]\[ -3 + 5 = 2 \][/tex]

Putting it all together, we get:
[tex]\[ (f+g)(x) = 4x^3 + x^2 + 5x + 2 \][/tex]

So, \((f+g)(x)\) is:
[tex]\[ 4x^3 + x^2 + 5x + 2 \][/tex]

If you want to find the value of \((f+g)(x)\) at \(x = 1\):

Substitute \(x = 1\) into \((f+g)(x)\):
[tex]\[ (f+g)(1) = 4(1)^3 + (1)^2 + 5(1) + 2 \][/tex]

Calculate the value step-by-step:
[tex]\[ = 4(1) + 1 + 5 + 2 \][/tex]
[tex]\[ = 4 + 1 + 5 + 2 \][/tex]
[tex]\[ = 12 \][/tex]

Therefore, \((f+g)(1)\) is:
[tex]\[ 12 \][/tex]

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