- Apply the binomial theorem to \((3c + d^2)^6\) with \(A=3c\), \(B=d^2\), and \(n=6\).
- Calculate the seven terms using binomial coefficients \(\binom{6}{k}\) for \(k=0\) through \(6\).
- Sum the terms to obtain the full expansion: \(729 c^6 + 1458 c^5 d^2 + 1215 c^4 d^4 + 540 c^3 d^6 + 135 c^2 d^8 + 18 c d^{10} + d^{12}\).
- The correct option is \(\boxed{e}\).
Explanation
- Applying the Binomial Theorem
To expand the expression \((3c + d^2)^6\), we apply the Binomial Theorem, which states that for any non-negative integer \(n\):
\[(A + B)^n = \sum_{k=0}^{n} \binom{n}{k} A^{n-k} B^k\]
In this problem, \(A = 3c\), \(B = d^2\), and \(n = 6\). We will calculate each term for \(k = 0, 1, 2, 3, 4, 5, 6\). The binomial coefficients \(\binom{6}{k}\) are the numbers in the seventh row of Pascal's triangle: \(1, 6, 15, 20, 15, 6, 1\).
- Calculating Each Term
We calculate each of the seven terms individually:
- \(k=0\): \(\binom{6}{0} (3c)^6 (d^2)^0 = 1 \times 729 c^6 \times 1 = 729 c^6\)
- \(k=1\): \(\binom{6}{1} (3c)^5 (d^2)^1 = 6 \times 243 c^5 \times d^2 = 1458 c^5 d^2\)
- \(k=2\): \(\binom{6}{2} (3c)^4 (d^2)^2 = 15 \times 81 c^4 \times d^4 = 1215 c^4 d^4\)
- \(k=3\): \(\binom{6}{3} (3c)^3 (d^2)^3 = 20 \times 27 c^3 \times d^6 = 540 c^3 d^6\)
- \(k=4\): \(\binom{6}{4} (3c)^2 (d^2)^4 = 15 \times 9 c^2 \times d^8 = 135 c^2 d^8\)
- \(k=5\): \(\binom{6}{5} (3c)^1 (d^2)^5 = 6 \times 3 c \times d^{10} = 18 c d^{10}\)
- \(k=6\): \(\binom{6}{6} (3c)^0 (d^2)^6 = 1 \times 1 \times d^{12} = d^{12}\)
- Finalizing the Expansion and Selecting the Correct Option
Combining all the calculated terms, we get the complete expansion:
\[729 c^6 + 1458 c^5 d^2 + 1215 c^4 d^4 + 540 c^3 d^6 + 135 c^2 d^8 + 18 c d^{10} + d^{12}\]
Comparing this result to the given options, it matches option (e).
Examples
The Binomial Theorem is a powerful tool in various fields, such as finance and probability. For instance, if you are calculating compound interest over multiple periods or determining the probability of a specific outcome in a series of independent events (like a sequence of coin flips), you often encounter binomial expressions. Expanding these expressions allows for a clearer understanding of the individual contributions of each variable or parameter, facilitating more accurate modeling and forecasting in real-world systems.