How would i do this problem: It says

The total number of lights in a triangular rig with n rows is given by the function T(n) as given. Find the number of lights in triangular rigs with 1 to 10 rows.
T(n)=1/2n^2+1/2n

Question

How would i do this problem: It says 

The total number of lights in a triangular rig with n rows is given by the function T(n) as given. Find the number of lights in triangular rigs with 1 to 10 rows. 
T(n)=1/2n^2+1/2n

phi · Answer

It sounds like 10 separate problems
substitute 1 for n  in the formula to get 
T(1) =0.5 * 1^2 + 0.5*1 = 0.5+ 0.5 = 1
do the same for n=2,3,...10

anonymous · Answer

oh okay!(:

phi · Answer

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you could also count them, but that would be tedious