Apps. and Interpretation for IBDP Maths Ebook 2 | Page 39

2
4 . The relationship between two variables N and t can be modelled by ln N �aln t � b , where a , b� , N , t � 0. A graph of ln N against ln t shows a straight line such that it passes through the points ( 2.5,1 ) and ( 5 , 0 ) .
( a ) Find the values of

2

( i ) a ;
( ii ) b .
( b ) Hence , express N in terms of t .
[ 4 ]
[ 3 ] www . seprodstore . com
29