To find the equation of the tangent line to the curve defined by y = 4x – 3x² at the point (2, 4), we follow these steps:
- Find the derivative: The derivative of a function gives us the slope of the tangent line at any point on that curve. Let’s find the derivative of the function:
- Given: y = 4x – 3x²
- Using the power rule, the derivative is:
- dy/dx = 4 – 6x
Now we can find the slope of the tangent line at the point (2, 4):
- Evaluate the derivative at x = 2:
- Substituting x = 2 into the derivative:
- dy/dx = 4 – 6(2) = 4 – 12 = -8
So, the slope of the tangent line at the point (2, 4) is -8.
- Use the point-slope form to write the equation of the tangent line: The point-slope form of the line is given by:
y – y1 = m(x – x1)
Where:
- (x1, y1) is the point (2, 4) and m is the slope, which we found to be -8.
Plugging in these values:
y – 4 = -8(x – 2)
Now, let’s simplify this equation:
- Multiply both sides by -1:
y – 4 = -8x + 16
Adding 4 to both sides, we get:
y = -8x + 20
The equation of the tangent line to the curve y = 4x – 3x² at the point (2, 4) is:
y = -8x + 20