Mathematics

For what value of y is the expression (frac{y + 2}{y^{2} – 3y – 10})…

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.