Science:Math Exam Resources/Courses/MATH110/December 2013/Question 10 (b)/Statement

Find constants $a$ and $b$ so that the function

$f(x)={\begin{cases}x^{2}-2x+1&{\text{if }}x\leq 2\\ax+b&{\text{if }}x>2\end{cases}}$

is differentiable everywhere.