Question #7adc3
1 Answer
Feb 11, 2017
Explanation:
#•f(1)=g(1)#
#rArr3/(a-b)=(a+b)/1#
#color(blue)"cross multiply"#
#rArr(a+b)(a-b)=3to(1)#
#•f(2).g(2)=4#
#rArr3/(2a-b)xx(2b+a)/1=4#
#rArr3(2b+a)=4(2a-b)#
#rArr6b+3a=8a-4b#
#rArr10b=5arArrcolor(red)(b=1/2a)# Substitute
#b=1/2a" into " (1)#
#rArr(a+b)(a-b)=3#
#rArra^2-b^2=3#
#rArra^2-(1/2a)^2=3#
#rArra^2-1/4a^2=3rArr3/4a^2=3#
#rArra^2=4rArra=+-2#
#a>0rArra=2#
#"and " b=1/2arArrb=1#