66
kaymant
·2009-12-11 02:51:11
Hint: The numbers a,b,c can be thought of as the roots of a cubic.
1
arpan sinha
·2009-12-11 03:10:16
f(x)= x^3 - 6x^2+9x +k.
i think we hv to find out the derivative& equate to 0.
this gives the tangents at those pts to be parallel to x axis.
now we pull the graph by k upwards & down wards.
thus we get the required proof ensuring that the graph will not exceed 0&4.
this is just a hint.....
62
Lokesh Verma
·2009-12-11 04:10:53
arpan .. very bad.. i did this one in the class and u are not letting others to do this :(
62
Lokesh Verma
·2009-12-11 04:25:00
no you are correct..
but i din get why abc>0??
uptil the 1st derivative part and the graph you are correct..
but i guess i should not interfere too much in Kaymant sir's post...
1
arpan sinha
·2009-12-11 04:57:11
srry!!!!!!!!!!
Nishant bhaiyya!!!!!!!
maafi chahta hoon!!!!!!!!!!!!!!!!