Q. Find the 2 nd term in the expansion of (4x−1)6 in simplest form.Answer:
Use Binomial Theorem: To find the 2nd term in the expansion of (4x−1)6, we will use the binomial theorem. The general form of the k-th term in the expansion of (a+b)n is given by T(k)=(k−1n)⋅an−k+1⋅bk−1, where (k−1n) is the binomial coefficient. For the 2nd term, k=2.
Calculate Binomial Coefficient: First, we calculate the binomial coefficient for the 2nd term, which is 6C1 (since k−1=2−1=1). 6C1 is the number of combinations of 6 items taken 1 at a time, which is simply 6.
Raise First Term to Power: Next, we raise the first term of the binomial, 4x, to the power of (6−2+1) which is 5. So, (4x)5=45×x5=1024x5.
Raise Second Term to Power: Then, we raise the second term of the binomial, −1, to the power of (2−1) which is 1. So, (−1)1=−1.
Multiply Coefficient and Terms: Now, we multiply the binomial coefficient by the powers of the first and second terms. The 2nd term of the expansion is 6×1024x5×(−1)=−6144x5.
Simplify the Expression: Finally, we simplify the expression to get the 2nd term in its simplest form. The 2nd term is −6144x5.
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