| if a_1  = 3 ,a_2 =2
a_(n+2)  = a_(n+1) +(a_1 /2)
find a_6  =?
mister W method
a_n  =A(((1+(√3))/2))^n +B(((1−(√3))/2))^n 
a_1 = A(((1+(√3))/2))+B(((1−(√3))/2))=3
a_2  = A(((1+(√3))/2))^2 +B(((1−(√3))/2))^2 =2
⇒A+B+(A−B)(√3) =6
⇒2(A+B)+(A−B)(√3) =4
A= ((4−(√3))/(√3)) , B = ((−4−(√3))/3)
a_n  = (((4−(√3))/(√3)))(((1+(√3))/2))^n −(((4+(√3))/(√3)))(((1−(√3))/2))^n 
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