Question
The equation of normal on point (2,4) to the parabola y2 = 8x is-
- x + y = 6
- x – y + 2 = 0
- x + y = 2
- None of these
Hint:
find out the slope of normal and use point and slope form to find the equation of normal.
The correct answer is: x + y = 6
x+y=6
Slope of tangent : dy/dx = 4/y
Slope of normal = -y/4
Equation of normal : y-4=-1(x-2)
y-4 = 2-x
x+y=6
we can also use equation of normal in slope form: y = mx – 2am – am3
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