Question #42cd3

Question

1169 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-02-10T13:49:44

If #F != f_1#

#f_2=(Ff_1)/(f_1-F)#

If #F != f_1# (to avoid dividing by #0#)

#F = (f_1f_2)/(f_1+f_2)#

#=>F(f_1+f_2)=f_1f_2#

#=>Ff_1 + Ff_2 = f_1f_2#

#=>Ff_2-f_1f_2 = -Ff_1#

#=>f_2(F-f_1)=-Ff_1#

#:.f_2=-(Ff_1)/(F-f_1)=(Ff_1)/(f_1-F)#