Continuity!!!

1 If the denominator is zero, then the function will be discontinuous at that point

So, let (4 - x^2)^0.5 = 0

x^2 = 4 => x = -2 or 2

The function is discontinuous when x = -2, 2

2 The left hand limit and right hand limit of a function should be equal in order that the function is continuous at that point

So, lim (x-> 1-) f(x) = limit (x->1+) f(x)

lim (x-> 1-) x^2 - 1 = lim (x-> 1+) 3x^3 + a

0 = 3 + a

a = -3

1. 當 x = +2 或 -2 時 (4 - x^2)^0.5 會等於 0 ，形成 1 / 0，所以在 x = -2 和 x = +2 會不連續。

2. 睇唔出有什麼地方會不連續。