Your Practice Paper – Applications and Interpretation HL for IBDP Mathematics
 19 Differentiation
 dy
 � � f�( x) : Derivative of the function y � f ( x)
 ( First derivative ) dx
 � Rules of differentiation : 1 . n f ( x) � x � f �( x)
 � nx �
 n 1
 2 .  | 
  f ( x) 
 � p( x) 
 � q( x) 
 � f 
 �( x) 
 � p�( x) 
 � q�( x) 
 | 
 3 .  | 
  f ( x) 
 �cp( x) 
 � f 
 �( x) 
 � cp�( x) 
 | 
 � Relationship between graph properties and the derivatives : 1 . f�( x) � 0 for a �x � b : f( x ) is increasing in the interval 2 . f�( x) � 0 for a �x � b : f( x ) is decreasing in the interval 3 . f�( a) � 0: ( a, f ( a )) is a stationary point of f( x ) 4 . f�( a) � 0 and f� ( x) changes from positive to negative at x� a: ( a, f ( a )) is a maximum point of f( x )
 5 . f�( a) � 0 and f� ( x) changes from negative to positive at x� a: ( a, f ( a )) is a minimum point of f( x )
 � Tangents and normals : 1 . f� ( a)
 : Slope of tangent at x� a
 2 .
 �1 f�( a)
 : Slope of normal at x� a
 3 . y � f ( a) � f �( a)( x � a) : Equation of tangent at x� a
 4 . y f 1 ( a � � �
 � ) � � ( ) f ( a) x � �
 � a � �
 � Derivatives of a function y � f ( x)
 :
 1 .
 2 .
 2 d y d �d �
 2 � d d d
 y�
 �� x x � x � n d y n dx
 : Equation of normal at x� a f��( x) : Second derivative
 ( n) � f ( x)
 : n -th derivative
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