To solve this problem, let's break it down step-by-step.
Step 1: Expand (1+2x)10 up to the fourth term in powers of x.
This is a binomial expansion problem where we expand (1+2x)10 using the Binomial Theorem:
(1+2x)10=∑k=010(k10)⋅(1)10−k⋅(2x)k
We are asked to expand up to and including the fourth term. So, we need the terms for k=0,1,2,3, and 4.
Terms Calculation:
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For k=0:
(010)⋅(1)10⋅(2x)0=1
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For k=1:
(110)⋅(1)9⋅(2x)1=10⋅2x=20x
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For k=2:
(210)⋅(1)8⋅(2x)2=45⋅4x2=180x2
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For k=3:
(310)⋅(1)7⋅(2x)3=120⋅8x3=960x3
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For k=4:
(410)⋅(1)6⋅(2x)4=210⋅16x4=3360x4
Thus, the expansion of (1+2x)10 up to the fourth term is:
1+20x+180x2+960x3+3360x4
Step 2: Use the expansion to evaluate (1.0002)10
To find (1.0002)10, we let x=0.0001 in our expansion (1+2x)10.
Substitute x=0.0001 into the expression:
1+20(0.0001)+180(0.0001)2+960(0.0001)3+3360(0.0001)4
Now, calculate each term:
- 20×0.0001=0.002
- 180×(0.0001)2=180×0.00000001=0.0000018
- 960×(0.0001)3=960×0.000000000001=0.000000096
- 3360×(0.0001)4=3360×0.0000000000000001=0.000000000336
Add these terms together:
1+0.002+0.0000018+0.000000096+0.000000000336≈1.0020019
Final Answer:
To four decimal places, (1.0002)10≈1.0020.
Would you like a detailed explanation of any specific part? Here are some related questions that might expand your understanding:
- How does the Binomial Theorem work in general for any expansion (a+b)n?
- What are binomial coefficients, and how are they calculated?
- Can the expansion be used for other values of n or different terms in the series?
- What are some real-world applications of binomial expansion?
- Why do we approximate (1.0002)10 using the first few terms only?
Tip: When dealing with binomial expansions for small changes (like 1.0002), the first few terms usually provide a very close approximation.