Q. Find the 2nd term in the expansion of (x+4)3 in simplest form.Answer:
Use Binomial Theorem: To find the 2nd term in the expansion of (x+4)3, we can use the binomial theorem, which states that the nth term in the expansion of (a+b)n is given by nC(k−1)⋅an−k+1⋅bk−1, where nC(k−1) 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 3C1 (since k−1=2−1=1). 3C1 is the number of ways to choose 1 item from 3, which is 3.
Raise x to Power: Next, we raise the first term, x, to the power of (3−2+1), which is x(3−1)=x2.
Raise 4 to Power: Then, we raise the second term, 4, to the power of (2−1), which is 41=4.
Multiply Coefficients and Powers: Now, we multiply the binomial coefficient by the powers of x and 4 to get the 2nd term: 3×x2×4.
Simplify Expression: Simplify the expression by multiplying the constants: 3×4=12.
Final 2nd Term: Finally, we have the 2nd term in the expansion: 12x2.
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