Find all real numbers for which the rational expression is undefined.

Question

6x − 15

_______

x^2 − 49

Answer 1

IN GENERAL,I.E. IN ALL RATIONAL ALGEBRAIC FUNCTIONS, YOU FACTOR THE DENOMINATOR(S); ALL OF THOSE ZEROS ARE PROHIBITED BECAUSE OF THE PROHIBITION ON DIVISION BY ZERO.

 

YOU NEED TO UNDERSTAND AND REMEMBER THIS.

Answer 2

(6x-15) / (x²-49) is undefined when x²-49 = 0  (Division by zero is undefined)

 

                                                    (x-7)(x+7) = 0

 

                                                                x = ±7