For what value of y is the expression (frac{y + 2}{y^{2} – 3y – 10}) undefined?
-
A.
y = 0 -
B.
y = 2 -
C.
y = 3 -
D.
y = 5 -
E.
y = 10
Correct Answer: Option D
Explanation
(frac{y + 2}{y^2 – 3y – 10})
(y^2 – 3y – 10 = 0 implies y^2 – 5y + 2y – 10 = 0)
(y(y – 5) + 2(y – 5) = 0)
((y – 5)(y + 2) = 0)
(frac{y + 2}{(y – 5)(y + 2)} = frac{1}{y – 5})
(therefore) At y = 5, the expression (frac{y + 2}{y^2 – 3y – 10}) is undefined.