f(0)=0,f(1)=1,f(2)=2 Given, f(x)=f(x−2)+f(x−3),x=3,4,5,... The given function is known as "Reccurrence function". ‌ put ‌x=3,f(3)‌=f(1)+f(0) ‌=1+0=1 ‌ put ‌x=4,f(4)‌=f(2)+f(1) ‌=2+1⇒3 ‌ put ‌x=5,f(5)‌=f(3)+f(2) ‌=1+2⇒3 ‌ put ‌x=6,f(6)‌=f(4)+f(3) ‌=3+1⇒3+1⇒4 ‌ put ‌x=7,f(7)‌=f(5)+f(4) ‌=3+3⇒6 ‌ put ‌x=8,f(8)‌=f(6)+f(5) ‌=3+4⇒7 ‌ put ‌x=9,f(9)‌=f(7)+f(6) ‌=6+4⇒10 ‌ Hence, ‌‌f(9)=10