Q. If a1=4,a2=5 and an=2an−1+an−2 then find the value of a4.Answer:
Understand Recursive Formula: Understand the recursive formula and initial conditions.The recursive formula given is an=2an−1+an−2, which means each term is the sum of twice the previous term and the term before that. We are given a1=4 and a2=5 as initial conditions.
Find a3 Value: Find the value of a3 using the recursive formula.Using the formula an=2an−1+an−2, we substitute n=3 to find a3.a3=2a2+a1a3=2×5+4a3=10+4a3=14
Find a4 Value: Find the value of a4 using the recursive formula and the values of a2 and a3. Now we use the formula an=2an−1+an−2 with n=4. a4=2a3+a2a4=2×14+5a4=28+5a4=33
More problems from Write and solve direct variation equations