Question
Question: For real values of x, the expression \(\frac{(x - b)(x - c)}{x - a}\) will assume all real values pr...
For real values of x, the expression x−a(x−b)(x−c) will assume all real values provided -
A
a £ c £ b
B
b ³ a ³ c
C
b £ c £ a
D
a ³ b ³ c
Answer
b ³ a ³ c
Explanation
Solution
y = (x−a)x2−(b+c)x+bc
Ž x2 – (b + c + y) x + bc + ay – 0
D ³ 0
Ž (b + c + y)2 –4 (bc + ay) ³ 0
Ž y2 + 2(b + c – 2a) y + (b – c)2 ³ 0
D £ 0
Ž 4(b + c – 2a)2 – 4 (b – c)2 £ 0
Ž (2b – 2a) (2c – 2a) £ 0
Ž (a – b) (a – c) £ 0
Ž b £ a £ c if (b < c) or (c £ a £ b) if (c < b)