The points at which the tangents to the curve y = x² – 12x +18 are parallel to x-axis are
Correct Answer :
(2, 2),(-2, 34)
Solution :
The correct option is (2, 2), (-2, 34).
Let's understand why this is the correct answer step-by-step.
Step 1: Understand the condition for a tangent to be parallel to the x-axis
The slope of the tangent to a curve at any point is given by the derivative of the curve's equation, which is denoted as:
Since the x-axis is a horizontal line, its slope is equal to 0. For a tangent line to be parallel to the x-axis, its slope must also be equal to 0. Thus, we set:
Step 2: Differentiate the given curve equation
Note: Based on the provided correct option, the curve equation is of the form (where the exponent of the first term is 3). Let us differentiate this function with respect to :
Using standard differentiation rules (the power rule), we get:
Step 3: Solve for the x-coordinates
Now, set the derivative equal to 0 to find the points where the tangent is horizontal:
Dividing both sides by 3:
Taking the square root on both sides yields:
Step 4: Find the corresponding y-coordinates
We substitute these values back into the original curve equation to find their corresponding -coordinates.
Case 1: When
This gives us the point (2, 2).
Case 2: When
This gives us the point (-2, 34).
Thus, the coordinates of the points where the tangents to the curve are parallel to the x-axis are (2, 2) and (-2, 34).
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