Math Problem Statement

find no of different dissimilar terms in sum 1+x) ^2012+(1+x^2) 2011+(1+x^3) 2010

Solution

We are tasked with finding the number of different dissimilar terms in the following expression:

(1+x)2012+(1+x2)2011+(1+x3)2010(1 + x)^{2012} + (1 + x^2)^{2011} + (1 + x^3)^{2010}

Breaking it down term by term:

  1. (1+x)2012(1 + x)^{2012}:

    • This is a binomial expansion of the form (a+b)n(a + b)^n, which gives terms of the form: (2012k)xkfork=0,1,2,,2012\binom{2012}{k} x^k \quad \text{for} \quad k = 0, 1, 2, \dots, 2012
    • Therefore, the exponents of xx in this expansion will range from 00 to 20122012.
    • So, the possible powers of xx in this part are: x0,x1,x2,,x2012x^0, x^1, x^2, \dots, x^{2012}.
  2. (1+x2)2011(1 + x^2)^{2011}:

    • Similarly, this is a binomial expansion of the form (a+b)n(a + b)^n, but here, the second term is x2x^2.
    • The terms are of the form: (2011k)(x2)k=(2011k)x2kfork=0,1,2,,2011\binom{2011}{k} (x^2)^k = \binom{2011}{k} x^{2k} \quad \text{for} \quad k = 0, 1, 2, \dots, 2011
    • The powers of xx will now range from x0,x2,x4,,x4022x^0, x^2, x^4, \dots, x^{4022} (because the highest power is 2×2011=40222 \times 2011 = 4022).
  3. (1+x3)2010(1 + x^3)^{2010}:

    • This binomial expansion involves x3x^3, and the terms will be of the form: (2010k)(x3)k=(2010k)x3kfork=0,1,2,,2010\binom{2010}{k} (x^3)^k = \binom{2010}{k} x^{3k} \quad \text{for} \quad k = 0, 1, 2, \dots, 2010
    • The powers of xx here will be x0,x3,x6,,x6030x^0, x^3, x^6, \dots, x^{6030} (since the highest power is 3×2010=60303 \times 2010 = 6030).

Total distinct terms:

Now, we combine the possible powers of xx from all three expansions. We have:

  • Powers from (1+x)2012(1 + x)^{2012}: x0,x1,x2,,x2012x^0, x^1, x^2, \dots, x^{2012}
  • Powers from (1+x2)2011(1 + x^2)^{2011}: x0,x2,x4,,x4022x^0, x^2, x^4, \dots, x^{4022}
  • Powers from (1+x3)2010(1 + x^3)^{2010}: x0,x3,x6,,x6030x^0, x^3, x^6, \dots, x^{6030}

We need to find the total number of distinct exponents, so we consider the union of these three sets of exponents:

  • The first set includes all integers from 0 to 2012.
  • The second set includes all even integers from 0 to 4022.
  • The third set includes all multiples of 3 from 0 to 6030.

To count the distinct powers of xx, we need to consider how these overlap and combine.

Step-by-step counting:

  • Integers from 0 to 2012: This contributes 2013 distinct terms {0,1,2,,2012}\{0, 1, 2, \dots, 2012\}.
  • Even integers from 0 to 4022: These overlap with the previous set. There are 10071007 even integers up to 2012, which have already been counted. The remaining even integers from 2014 to 4022 contribute 10051005 new distinct terms.
  • Multiples of 3 from 0 to 6030: We already have multiples of 3 within the first two sets (such as 0, 3, 6, etc.). There are 671 multiples of 3 up to 2012, and 335 multiples of 3 from 2013 to 4022. The remaining multiples of 3 from 4023 to 6030 contribute additional terms.

Combining all the contributions and removing overlaps, the total number of distinct terms is:

2013+1005+670=36882013 + 1005 + 670 = 3688

Thus, the number of different dissimilar terms in the given sum is 3688.

Would you like further details or have any other questions?

Here are 5 related questions you may find interesting:

  1. How would the result change if the powers in the second binomial were x4x^4 instead of x2x^2?
  2. Can you find the number of distinct terms in (1+x2)2011(1 + x^2)^{2011} alone?
  3. What would the number of terms be if all powers were increased by 1 in each binomial?
  4. How would the distribution of powers change if xnx^n was used in the expansions?
  5. What is the effect of subtracting (1+x2)2011(1 + x^2)^{2011} from the original sum?

Tip: When combining terms with different powers, always look out for overlaps to avoid over-counting terms.

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Math Problem Analysis

Mathematical Concepts

Algebra
Binomial Expansion
Polynomial Exponents
Set Theory

Formulas

Binomial expansion: (a + b)^n = Σ (n choose k) a^(n-k) b^k
Power of terms: (1 + x^m)^n yields terms x^(m*k)

Theorems

Binomial Theorem

Suitable Grade Level

Grades 11-12