Answer is: option3
1.5Solution:
We are given the function:
\[ f(x) = 3x^2 - 4x + 2 \] Find \( f(1) \) \[ f(1) = 3(1)^2 - 4(1) + 2 = 3 - 4 + 2 = 1 \] Find \( f'(x) \)Differentiate \( f(x) \):
\[ f'(x) = \frac{d}{dx} (3x^2 - 4x + 2) = 6x - 4 \]Now, evaluate \( f'(1) \):
\[ f'(1) = 6(1) - 4 = 6 - 4 = 2 \] Equation of the Tangent Line at \( x = 1 \)The tangent line follows the point-slope formula:
\[ y - f(1) = f'(1)(x - 1) \]Substituting values:
\[ y - 1 = 2(x - 1) \] \[ y = 2x - 2 + 1 \] \[ y = 2x - 1 \]So, the tangent line equation is:
\[ L(x) = 2x - 1 \] Finding the Smallest \( x \) for \( |f(x) - L(x)| > 0.5 \)From the computed table, we observe that the error \( |f(x) - L(x)| \) exceeds 0.5 for the first time at \( x = 1.5 \).
x | f(x) | L(x) | |f(x) - L(x)| |
---|---|---|---|
1.3 | 1.87 | 1.6 | 0.27 |
1.4 | 2.28 | 1.8 | 0.48 |
1.5 | 2.75 | 2.0 | 0.75 |
1.6 | 3.28 | 2.2 | 1.08 |
1.7 | 3.87 | 2.4 | 1.47 |
Thus, the smallest value of \( x \) for which the error is more than 0.5 is: 1.5