If the tangent line to [tex]\( y=f(x) \)[/tex] at [tex]\( (6,5) \)[/tex] passes through the point [tex]\( (0, 4) \)[/tex], find [tex]\( f(6) \)[/tex] and [tex]\( f^{\prime}(6) \)[/tex].

A. [tex]\( f(6) = 5 \)[/tex], [tex]\( f^{\prime}(6) = 5 \)[/tex]
B. [tex]\( f(6) = 5 \)[/tex], [tex]\( f^{\prime}(6) = \frac{1}{5} \)[/tex]
C. [tex]\( f(6) = 5 \)[/tex], [tex]\( f^{\prime}(6) = \frac{1}{6} \)[/tex]
D. [tex]\( f(6) = 5 \)[/tex], [tex]\( f^{\prime}(6) = \frac{1}{4} \)[/tex]



Answer :

To solve this problem, we can follow these steps:

1. Recognize that the tangent line to [tex]\( y = f(x) \)[/tex] at [tex]\((6, 5)\)[/tex] means that [tex]\( f(6) = 5 \)[/tex].

2. We need to find the slope of the tangent line, [tex]\( f'(x) \)[/tex], at [tex]\( x = 6 \)[/tex]. This slope can be determined by the points [tex]\( (6, 5) \)[/tex] and [tex]\( (0, 4) \)[/tex], which lie on the tangent line.

3. The slope [tex]\( m \)[/tex] of a line passing through two points [tex]\( (x_1, y_1) \)[/tex] and [tex]\( (x_2, y_2) \)[/tex] is calculated by the formula:
[tex]\[ m = \frac{y_2 - y_1}{x_2 - x_1} \][/tex]

4. Plugging in the given points [tex]\((6, 5)\)[/tex] and [tex]\((0, 4)\)[/tex] into the formula to find the slope:
[tex]\[ m = \frac{4 - 5}{0 - 6} = \frac{-1}{-6} = \frac{1}{6} \][/tex]

5. Thus, the slope of the tangent line at [tex]\( x = 6 \)[/tex], which is [tex]\( f'(6) \)[/tex], is [tex]\( \frac{1}{6} \)[/tex].

6. Therefore, the values are:
[tex]\[ f(6) = 5 \quad \text{and} \quad f'(6) = \frac{1}{6} \][/tex]

The correct answer is:
c. [tex]\( f(6) = 5 \quad \text{and} \quad f'(6) = \frac{1}{6} \)[/tex]