
Jeremiah T. answered 06/06/20
Award Winning Tutor for Algebra and Precalculus
The answers are simple, provided you think about the question correctly. Notice you already have the value of f(x) when x = 7. It's 3, because we have the coordinates (7, 3). So f(7) = 3.
To find f'(7), because the derivative is slope, find the slope of the line that passes through the two points, using the slope formula.
f'(7) = (2 - 3)/(0 - 7) = -1/-7 = 1/7
Or, a more complex solution is to find the equation of the line that passes through the two points, and then find the equation's derivative. That goes like this:
y = mx + b
y = (1/7)x + 2
y is the same as f(x). So f'(x) = 1 * (1/7)x^0 = 1/7. Let me know if this is helpful!