Question

Determine all numbers at which the function is continuous.

Answer 1

Answer: Option a.

Step-by-step explanation:

Make the denominator equal to zero and solve for x, as following:

$x^{2}+8x-9=0$

Choose two numbers whose sum is 8 and whose product is 9.

Then:

$(x-1)(x+9)=0\\x=1\\x=-9$

Therefore, based on this, you can conclude that the function is continuous at everty real number except x=1 and x=-9.