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Application Of Derivatives

Question
CBSEENMA12035055

Prove that the tangents to the curve Y = x2 – 5x + 6 at the points (2, 0) and (3, 0) are at right angles.

Solution

The equation of the curve is
y = x– 5x + 6
therefore space space space space dy over dx space equals 2 straight x minus 5
Let straight m subscript 1 comma space space straight m subscript 2 be slopes of tangents to the curve at the points (2, 0), (3, 0).
therefore space space space space straight m subscript 1 equals space space value space of space dy over dx space at space left parenthesis 2 comma space 0 right parenthesis space equals 2 left parenthesis 2 right parenthesis minus 5 space equals 4 minus 5 space equals space minus 1
space space space space space space space space straight m subscript 2 space equals space value space of space dy over dx space at space left parenthesis 3 comma space 0 right parenthesis space equals space 2 left parenthesis 3 right parenthesis space minus space 5 space equals space 6 minus 5 space equals space 1
therefore space space space straight m subscript 1 straight m subscript 2 space equals space left parenthesis negative 1 right parenthesis thin space left parenthesis 1 right parenthesis space equals space minus 1
therefore space tangents space to space the space given space curve space at space left parenthesis 2 comma space 0 right parenthesis comma space left parenthesis 3 comma space 0 right parenthesis space are space perpendicular space to space each space other.