12. The function
\[ f(x) = \begin{cases} 4 - x^2 & \text{if } x \leq 1 \\ mx + b & \text{if } x > 1 \end{cases} \]
is continuous and differentiable for all real numbers. What must be the values of \( m \) and \( b \) ?
Answer is: option4
Solution:
.
