What is the value of 1/1^2 + 1/2^2+ 1/3^2 + 1/4^2 + and so on ​

What is (28 + 7 + 6 + 3) x 1/2 show your work

Consider the function y = f(x)=3^x the values of f(1/2) and f(1/4). rounded to the nearest hundredth, are__and__ respectively

Which is a true statement about an exterior angle of a triangle a. it is formed by two segments that are not sides of the triangle, b. it forms a linear pair with one of the interior angles of the triangle, c. it is complementary to one of the interior angles of the triangle. d. it is formed by two segments that are sides of the triangle.