00:01
So here we want to determine if the limits exist.
00:05
And for a, we want a limit when x goes to 3.
00:10
4, 3x to the 4th plus 2x squared minus 5.
00:17
Well, this is continuous for all real numbers x.
00:21
So this is just 3 times 3 to the 4th plus 2 times 3 squared to minus 5, which is equal to 256.
00:32
For b, we want the limit when x goes to 5 for 4x divided by x minus 5.
00:41
But when x goes to 5, the denominator here goes to 0.
00:46
The numerator goes to 20, so this goes to 20 over 0.
00:54
And when we go to 5 from the left, this will be smaller than 0, so this whole thing will be negative.
01:11
So the limit when x goes to 5 from the left, 4x over x minus 5, goes to negative infinity...