KCET2026MathematicsFunctions
The domain of the function x-7 9-x is
Options
- A[7, 9]
- B[7, 9)
- C(7, 9]
- D(7, 9)
Correct answer
B. [7, 9)
Step-by-step solution
For the function to be defined, the expression inside the square root must be non-negative and the denominator must not be zero. x-7 9-x 0 and 9-x 0 Multiplying the numerator and denominator by -1 , we get: x-7 x-9 0 The critical points are x = 7 and x = 9 . Using the wavy curve method, the expression x-7 x-9 is less than or equal to zero for x [7, 9] . Since the denominator cannot be zero, x 9 . Therefore, the domain of the function is x [7, 9) . Answer: [7, 9)