There are also hints for question.

4. ) a. ) Determine the curve whose curvature of tangent indicatrix is constant. b. ) Show that the unit brnormal of the involute I* = d + ( c - s ) E of F = 2 (s) is b* _ xb'+ ct 1( -5) x / x* where K is the curvature of " (s ) and I is the torsion of 2 (5 ) . Hints : 4 ) a . ) y ( s ) = = ( s ) I show it y ' ( s ) = = = KR , . 1 1 9 ( s ) - x E + K n + ( x b K- = ly'x y' ? 1 1 13 curvature of tangent indicatrix K, = constant = ( =)? 6 . ) ( 2 + ) ' = + ( c - 5) " E + ( c-s ) = = =_ E + (c-s) Kn' (24 )' = x ( c -s ) n ( * ) " = ( x " ( c - s ) + x ( - 1 ) ) ni+ x ( c- s) n = - - - 6 "* = ( a* ) ' x ( 2 * ) &quot