Discover new information and insights with the help of IDNLearn.com. Ask your questions and receive reliable, detailed answers from our dedicated community of experts.

Find the first four non-zero terms of the Maclaurin series for the function below:

[tex]\[ f(x) = 3e^{x^2} \][/tex]


Sagot :

To find the Maclaurin series for the given function [tex]\( f(x) = 3 e^{x^2} \)[/tex], we need to expand this function around [tex]\( x = 0 \)[/tex]. Let us first understand that the Maclaurin series for any function [tex]\( f(x) \)[/tex] is given by:

[tex]\[ f(x) = f(0) + f'(0)\frac{x}{1!} + f''(0)\frac{x^2}{2!} + f'''(0)\frac{x^3}{3!} + \cdots \][/tex]

In this case, [tex]\( f(x) = 3 e^{x^2} \)[/tex], we will calculate the necessary derivatives and evaluate them at [tex]\( x = 0 \)[/tex].

Step 1: Calculate [tex]\( f(0) \)[/tex]
[tex]\[ f(0) = 3 e^{0^2} = 3 e^0 = 3 \][/tex]

Step 2: Calculate the first derivative [tex]\( f'(x) \)[/tex] and find [tex]\( f'(0) \)[/tex]

Let’s find the first derivative:
[tex]\[ f(x) = 3 e^{x^2} \][/tex]
[tex]\[ f'(x) = 3 \left( e^{x^2} \right)' \][/tex]
Using the chain rule for [tex]\( e^{x^2} \)[/tex]:
[tex]\[ \frac{d}{dx} e^{x^2} = e^{x^2} \cdot \frac{d}{dx} (x^2) = 2x e^{x^2} \][/tex]
Thus:
[tex]\[ f'(x) = 3 \cdot 2x e^{x^2} = 6x e^{x^2} \][/tex]
Evaluating at [tex]\( x = 0 \)[/tex]:
[tex]\[ f'(0) = 6 \cdot 0 \cdot e^{0^2} = 0 \][/tex]

Step 3: Calculate the second derivative [tex]\( f''(x) \)[/tex] and find [tex]\( f''(0) \)[/tex]

Let's find the second derivative:
[tex]\[ f''(x) = \frac{d}{dx} (6x e^{x^2}) \][/tex]
Apply the product rule here:
[tex]\[ f''(x) = 6 \left( x \frac{d}{dx} (e^{x^2}) + e^{x^2} \frac{d}{dx} (x) \right) \][/tex]
[tex]\[ f''(x) = 6 \left( x \cdot 2x e^{x^2} + e^{x^2} \right) \][/tex]
[tex]\[ f''(x) = 6 \left( 2x^2 e^{x^2} + e^{x^2} \right) \][/tex]
[tex]\[ f''(x) = 6 \left( 2x^2 e^{x^2} + e^{x^2} \right) = 6 e^{x^2} (2x^2 + 1) \][/tex]
Evaluating at [tex]\( x = 0 \)[/tex]:
[tex]\[ f''(0) = 6 e^{0^2} (2(0)^2 + 1) = 6 \cdot 1 \cdot 1 = 6 \][/tex]

Step 4: Calculate the third derivative [tex]\( f'''(x) \)[/tex] and find [tex]\( f'''(0) \)[/tex]

Let's find the third derivative:
[tex]\[ f'''(x) = \frac{d}{dx} (6 e^{x^2} (2x^2 + 1)) \][/tex]
Apply the product rule:
[tex]\[ f'''(x) = 6 \left[ \frac{d}{dx} (e^{x^2}) (2x^2 + 1) + e^{x^2} \frac{d}{dx} (2x^2 + 1) \right] \][/tex]
[tex]\[ f'''(x) = 6 \left[ 2x e^{x^2} (2x^2 + 1) + e^{x^2} (4x) \right] \][/tex]
[tex]\[ f'''(x) = 6 \left[ 2x (2x^2 + 1) e^{x^2} + 4x e^{x^2} \right] \][/tex]
[tex]\[ f'''(x) = 6 \left[ (4x^3 + 2x) e^{x^2} + 4x e^{x^2} \right] \][/tex]
[tex]\[ f'''(x) = 6 \left[ 4x^3 e^{x^2} + 2x e^{x^2} + 4x e^{x^2} \right] \][/tex]
[tex]\[ f'''(x) = 6 \left[ 4x^3 e^{x^2} + 6x e^{x^2} \right] \][/tex]
[tex]\[ f'''(x) = 6 e^{x^2} (4x^3 + 6x) \][/tex]
Evaluating at [tex]\( x = 0 \)[/tex]:
[tex]\[ f'''(0) = 6 \cdot e^{0^2} (4(0)^3 + 6 \cdot 0) = 0 \][/tex]

Step 5: Calculate the fourth derivative [tex]\( f^{(4)}(x) \)[/tex] and find [tex]\( f^{(4)}(0) \)[/tex]

Continuing, we need the fourth derivative:
[tex]\[ f^{(4)}(x) = \frac{d}{dx} \left[ 6 e^{x^2} (4x^3 + 6x) \right] \][/tex]
Again, use the product rule:
[tex]\[ f^{(4)}(x) = 6 \left[ \frac{d}{dx} (e^{x^2}) (4x^3 + 6x) + e^{x^2} \frac{d}{dx} (4x^3 + 6x) \right] \][/tex]
[tex]\[ f^{(4)}(x) = 6 \left[ 2x e^{x^2} (4x^3 + 6x) + e^{x^2} (12x^2 + 6) \right] \][/tex]
[tex]\[ f^{(4)}(x) = 6 \left[ 2x (4x^3 + 6x) e^{x^2} + e^{x^2} (12x^2 + 6) \right] \][/tex]
[tex]\[ f^{(4)}(x) = 6 \left[ (8x^4 + 12x^2) e^{x^2} + 12x^2 e^{x^2} + 6 e^{x^2} \right] \][/tex]
[tex]\[ f^{(4)}(x) = 6 \left[ 8x^4 e^{x^2} + 24x^2 e^{x^2} + 6 e^{x^2} \right] \][/tex]
Evaluating at [tex]\( x = 0 \)[/tex]:
[tex]\[ f^{(4)}(0) = 6 (8(0)^4 + 24(0)^2 + 6)e^{0^2} = 36 \][/tex]

So, summarizing the coefficients:
- [tex]\( f(0) = 3 \)[/tex]
- [tex]\( f'(0) = 0 \)[/tex]
- [tex]\( f''(0) = 6 \)[/tex]
- [tex]\( f'''(0) = 0 \)[/tex]
- [tex]\( f^{(4)}(0) = 36 \)[/tex]

Thus, the first four non-zero terms of the Maclaurin series for [tex]\( f(x) = 3 e^{x^2} \)[/tex] are:

[tex]\[ 3 + \frac{6}{2!} x^2 + \frac{36}{4!} x^4 \][/tex]
Simplifying:
[tex]\[ 3 + 3 x^2 + \frac{3}{2} x^4 \][/tex]

Which results in:
[tex]\[ f(x) = 3 + 3x^2 + \frac{3}{2}x^4 \][/tex]

So, the first four non-zero terms of the Maclaurin series for [tex]\( f(x) = 3 e^{x^2} \)[/tex] are:

[tex]\[ 3, 3x^2, \frac{3}{2}x^4 \][/tex]
We appreciate your participation in this forum. Keep exploring, asking questions, and sharing your insights with the community. Together, we can find the best solutions. IDNLearn.com is committed to providing the best answers. Thank you for visiting, and see you next time for more solutions.