Question

Given The recourse recursive formula, find the first four terms:

Answer 1

Answer:

c

Step-by-step explanation:

we are given that

$\displaystyle a_{n} = - 3 \: \cdot a_{n - 1} \\ a_{1} = 45$

we are already given our first term i.e 45

for second term

$\displaystyle a_{2} = - 3 \: \cdot a_{2- 1}$

simplify substraction:

$\displaystyle a_{2} = - 3 \: \cdot a_{1}$

since we have $a_1=45$

substitute:

$\displaystyle a_{2} = - 3 \: \cdot 45$

simplify multiplication:

$\displaystyle a_{2} = - 135$

for third term

$\displaystyle a_{3} = - 3 \: \cdot a_{3- 1}$

simplify Substraction:

$\displaystyle a_{3} = - 3 \: \cdot a_{2}$

as $a_2=-135$

substitute:

$\displaystyle a_{3} = - 3 \: \cdot - 135$

simplify multiplication:

$\displaystyle a_{3} = 405$

for forth term

$\displaystyle a_{2} = - 3 \: \cdot a_{4- 1}$

simplify Substraction:

$\displaystyle a_{2} = - 3 \: \cdot a_{3}$

substitute:

$\displaystyle a_{2} = - 3 \: \cdot 405$

simplify multiplication:

$\displaystyle a_{2} = - 1215$

hence,

the first four terms are 45,-135,405,-1215

Answer 2

Step-by-step explanation:

hence,

the first four terms are 45,-135,405,-1215