Question

Let $f(x)= \begin{cases} x^3-x^2+10 x-7, & x \leq 1 \\\ -2 x+\log _2\left(b^2-4\right), & x>1\end{cases}$ Then the set of all values of $b$, for which $f(x)$ has maximum value at $x=1$, is :

• A. $(-6,-2)$
• B. $(2,6)$
• C. $[-6,-2) \cup(2,6]$
• D. $[-\sqrt{6},-2) \cup(2, \sqrt{6}]$

Answer 1

Answer: (C)

$[-6,-2) \cup(2,6]$

Answer 2

The correct option is (C): $[-6,-2) \cup(2,6]$