NEED HELP WITH ADDITIONAL MATHEMATICS

[Kdhash]

October/November 2011 variant 21 question number 2

 

[kim anika]

3x+c=x^2+9x+k
x^2+6x+k=0
as line is tangent b^2-4ac=0
6^2-(4*1*k-c)
36-4k+3c=0
4k=36+4c
k=9+c

 

[Kdhash]

3x+c=x^2+9x+k
x^2+6x+k=0
as line is tangent b^2-4ac=0
6^2-(4*1*k-c)
36-4k+3c=0
4k=36+4c
k=9+c

how did u get 3c

 

[kim anika]

how did u get 3c

ooops!!!!!its actually 4c sry!!!!!

 

[Mau Cabby]

what about question number 4 or 5, the one about d/dx of x^2lnx, hence
⌠
⌡ xlnx dx???