Science:Math Exam Resources/Courses/MATH110/December 2015/Question 01 (a)/Hint 1

Recall that the derivative of a function at any point $x=a$, equals to the slope of the tangent line to the function at that point i.e. $f'(a)=m_{\text{tan}}(a)$.

Moreover, the tangency point satisfy both the equation of the line and the function equation.