Soru
(1 point) Let f(x)=(9)/(4pi -8x) Then the slope of the tangent : line to the graph of y=f(x) at the point (pi ,-(9)/(4pi )) is the limit as x tends to 3.14 of the following expression square The value of this limit is square It follows that the equation of the tangent line is y= square
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Profesyonel · 6 yıl öğretmeni
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Cevap
To find the slope of the tangent line to the graph of
at the point
, we need to find the derivative of
and evaluate it at
.The derivative of
is given by:
f'(x) = \frac{d}{dx}\left(\frac{9}{4\pi - 8x}\right)
Using the quotient rule, we have:
f'(x) = \frac{9 \cdot (-8)}{(4\pi - 8x)^2} = \frac{-72}{(4\pi - 8x)^2}
Now, we can evaluate
at
:
f'(\pi) = \frac{-72}{(4\pi - 8\pi)^2} = \frac{-72}{(-4\pi)^2} = \frac{-72}{16\pi^2} = \frac{-9}{4\pi^2}
Therefore, the slope of the tangent line to the graph of
at the point
is
.Next, we need to find the value of the limit as
tends to
of the expression
.Substituting
and
, we have:
\lim_{x \to \pi} \frac{f(x) - f(\pi)}{x - \pi} = \lim_{x \to \pi} \frac{\frac{9}{4\pi - 8x} + \frac{9}{4\pi}}{x - \pi}
Simplifying the expression, we get:
\lim_{x \to \pi} \frac{9}{(4\pi - 8x)(4\pi)} \cdot \frac{4\pi}{x - \pi} = \lim_{x \to \pi} \frac{9}{(4\pi - 8x)(4\pi)(x - \pi)}
As
approaches
, the denominator approaches zero, so the limit is undefined.Therefore, the value of the limit is undefined.Finally, we can use the point-slope form of a linear equation to find the equation of the tangent line:
y - y_1 = m(x - x_1)
Substituting
,
, and
, we have:
y + \frac{9}{4\pi} = \frac{-9}{4\pi^2}(x - \pi)
Simplifying the equation, we get:
y = \frac{-9}{4\pi^2}(x - \pi) - \frac{9}{4\pi}
Therefore, the equation of the tangent line is
.