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A curve has the equation y = −x³ + 3x² - 4x + 2. (i) Find the gradient of the normal to the curve at the point where the curve intersects the y-axis. (ii) Find the angle this normal to the curve makes with the x-axis.​

User Alexmac
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Answer: -75.96°

(i) To find the gradient of the normal to the curve at the point where the curve intersects the y-axis, we need to find the derivative of the curve equation and negate it. The derivative of y = -x³ + 3x² - 4x + 2 is given by:

dy/dx = -3x² + 6x - 4

At the point where the curve intersects the y-axis, x = 0. So, the gradient of the normal to the curve at this point is:

-3 * 0² + 6 * 0 - 4 = -4

(ii) To find the angle that this normal to the curve makes with the x-axis, we can use the tangent function. The tangent of an angle is equal to the gradient of a line, so we have:

tan(θ) = gradient of the normal = -4

The inverse tangent function (arctan) gives us the angle θ in radians, which we can then convert to degrees:

θ = arctan(-4) = -75.96°

So, the angle that the normal to the curve makes with the x-axis is approximately -75.96°.

Explanation:

User Nicola Ben
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