Question
Download Solution PDFWhat is the number of rational terms in the expansion of \((\sqrt{3}+5^\frac{1}{4})^{12}\)
Answer (Detailed Solution Below)
Detailed Solution
Download Solution PDFConcept:
A term in the binomial expansion of (a + b)n is given by Tk+1 = C(n, k) × an-k × bk.
For a term to be rational, the exponents of both √3 and 51/4 must be integers.
Formula Used:
In (√3)n-k, n-k must be even for it to be rational.
In (51/4)k, k must be a multiple of 4 for it to be rational.
Calculation:
Let n = 12:
⇒ For √3n-k to be rational, n-k must be even.
⇒ Since n = 12, k must also be even.
⇒ For (51/4)k to be rational, k must be a multiple of 4.
⇒ The values of k that satisfy both conditions (k is even and a multiple of 4) are:
⇒ k = 0, 4, 8, and 12.
⇒ These correspond to 4 rational terms in the expansion.
Hence, the Correct answer is Option 3.
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