The Student Room Group
Year 12s: what will be the first way you research your future options? >>
Year 12s: what will be the first way you research your future options? >>
Year 12s: what will be the first way you research your future options? >>

Easy C1 Diffrentiation question

I dont know why i am being an idiot but how would i find the stationary point after finding that:

dy/dx = 6x +6x-2

I know that i would have to set it to 0, but i thought that would mean that x would have to be 0 but the mark scheme is saying that the point is (-1,7)
6x + 6/x2 = 0

6x3 + 6 = 0

keep going....
Original post by Appazap
I dont know why i am being an idiot but how would i find the stationary point after finding that:

dy/dx = 6x +6x-2

I know that i would have to set it to 0, but i thought that would mean that x would have to be 0 but the mark scheme is saying that the point is (-1,7)


Yeah so set it =0 and divide through by 6 to get x+x−2=0x+x^{-2}=0. 0 can't be a solution because 0−20^{-2} is undefined. Multiplying through by x2x^2 yields x3+1=0x^3+1=0 which you can solve.
Reply 3
Avatar for Appazap
Appazap
OP
16
Original post by the bear
6x + 6/x2 = 0

6x3 + 6 = 0

keep going....


Original post by RDKGames
Yeah so set it =0 and divide through by 6 to get x+x−2=0x+x^{-2}=0. 0 can't be a solution because 0−20^{-2} is undefined. Multiplying through by x2x^2 yields x3+1=0x^3+1=0 which you can solve.


Thank you guys. Bit of a cheeky question if you ask me but makes sense now! :smile:

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you