The value of f(n) when n=4 is 14.
The function f(n)= n(n+3)/2 represents a mathematical relationship where n is the input variable. In this case, when n=4, we substitute this value into the function to find the corresponding output, denoted as f(4).
f(4)= 4(4+3)/2 = 4×7/2=28/2 =14.
So, when n is equal to 4, the function yields a value of 14. This means that if the given pattern continues, with increasing values of n, the function will produce a series of outputs, and for n=4, it results in f(n)=14.