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f(n)=2*(-3)^(n)
Complete the recursive formula of 
f(n).

{:[f(1)=◻],[f(n)=f(n-1)]:}

f(n)=2(3)n f(n)=2 \cdot(-3)^{n} \newlineComplete the recursive formula of f(n) f(n) .\newlinef(1)=f(n)=f(n1) \begin{array}{l} f(1)=\square \\ f(n)=f(n-1) \cdot \square \end{array}

Full solution

Q. f(n)=2(3)n f(n)=2 \cdot(-3)^{n} \newlineComplete the recursive formula of f(n) f(n) .\newlinef(1)=f(n)=f(n1) \begin{array}{l} f(1)=\square \\ f(n)=f(n-1) \cdot \square \end{array}
  1. Given Explicit Formula: We are given the explicit formula for the sequence: f(n)=2×(3)nf(n) = 2 \times (-3)^n. To find the recursive formula, we need to express f(n)f(n) in terms of f(n1)f(n-1).
  2. Find f(1)f(1): First, let's find f(1)f(1) by substituting n=1n = 1 into the explicit formula.\newlinef(1)=2×(3)1=2×(3)=6.f(1) = 2 \times (-3)^{1} = 2 \times (-3) = -6.\newlineSo, f(1)=6.f(1) = -6.
  3. Relationship between f(n)f(n) and f(n1)f(n-1): Now, let's find the relationship between f(n)f(n) and f(n1)f(n-1). We know that f(n)=2×(3)nf(n) = 2 \times (-3)^{n} and f(n1)=2×(3)n1f(n-1) = 2 \times (-3)^{n-1}.
  4. Divide f(n)f(n) by f(n1)f(n-1): To find f(n)f(n) in terms of f(n1)f(n-1), we can divide f(n)f(n) by f(n1)f(n-1):f(n)f(n1)=2(3)n2(3)n1.\frac{f(n)}{f(n-1)} = \frac{2 \cdot (-3)^n}{2 \cdot (-3)^{n-1}}.
  5. Simplify the Expression: Simplify the expression by canceling out common factors and using the properties of exponents: f(n)f(n1)=(3)n(3)n1=(3)n(n1)=(3)1=3\frac{f(n)}{f(n-1)} = \frac{(-3)^{n}}{(-3)^{n-1}} = (-3)^{n - (n - 1)} = (-3)^{1} = -3.
  6. Express f(n)f(n) in terms of f(n1)f(n-1): Now we can express f(n)f(n) in terms of f(n1)f(n-1):f(n)=3×f(n1)f(n) = -3 \times f(n-1).
  7. Combine Initial Condition: Combine the initial condition f(1)=6f(1) = -6 with the recursive relationship we just found: f(n)=3×f(n1)f(n) = -3 \times f(n-1), for n > 1.

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