And this problem, we're going to stick zero in immediately for the T and see if we can find the limit that way. So cosine π / sqrt 20 - 4, cosine 0 cosine zero is 1, so 20 - 4 * 1, sqrt 16, which is 4 cosine of π four. So we know is root 2 / 2. Now if we wanted to figure out F of 0, we'd literally stick zero in every time we see the T So F of 0 is doing the exact same work and it equals root 2 / 2. So F of 0 does equal the limit as T goes to 0 of F of T. Thus by our definition it has to be continuous at t = 0.