Question

Minor error in problem set 1, exercise 1A-4 b.

I don't know if this is the right place to post this, but perhaps someone from OCW could modify the following error:

it says:
f(x) = 1/2(f(x) + f(-x)) + 1/2(f(x) + f(-x))

but it should be:
f(x) = 1/2(f(x) + f(-x)) + 1/2(f(x) - f(-x))