1) f(1)=3.2
f(2)=(5/2)f(1)
f(3)=(5/2)f(2)=(5/2)*(5/2)f(1)=(5/2)²f(1)
f(4)=(5/2)*f(3)=(5/2)*(5/2)²f(1)=(5/2)³f(1)
f(5)=(5/2)*f(4)=(5/2)*(5/2)³f(1)=(5/2)⁴*f(1)=3.2*(5/2)⁴ =125
2)It is a geometrical sequence, so you can use formula
a(n)=a(1)*r^(n-1)
a(5)==3.2*(5/2)^(5-1)=3.2*(5/2)⁴ =125
