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Find an equation of the tangent line to the curve at the given point. y = 6 x cos x, (pi , -6 pi)

User Piotr Wach
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1 Answer

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Final answer:

To find the equation of the tangent line to the curve y = 6x cos x at the point (π, -6π), we calculate the derivative, evaluate it at x = π to get the slope -6, and then use the point-slope form to find the tangent line equation: y = -6x + 12π.

Step-by-step explanation:

To find an equation of the tangent line to the curve y = 6x cos x at the given point (π, -6π), we need to calculate the derivative of the function to find the slope of the tangent line at that point. The derivative of y with respect to x, using the product and chain rules, is:

y' = d/dx (6x cos x) = 6 cos x - 6x sin x

At x = π, we substitute π into the derivative to get the slope of the tangent line:

y'(π) = 6 cos(π) - 6π sin(π) = -6

Now we use the point-slope form of a line to write the equation of the tangent line:

y - y1 = m(x - x1), where (x1, y1) is the point on the curve and m is the slope.

For the given point (π, -6π) and slope -6, the equation of the tangent line is:

y - (-6π) = -6(x - π)

Simplifying this, we get:

y = -6x + 12π

User Sean James
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