Hi
If find the same answers but you haven't finished the last exercice
hi, im quite new to calculus and find it taxing but enjoyable. ive been given 4 questions to answer and have had a good go at them. how ever other class mates have got completely different answers to me , could some one pleae just check over them to make sure im going in the correct direct. many thanks
questions.doc
Hi, thanks for the reply, as for the last question. What else do I have to do to it? Do I have to differentiate the previous differentiated formula and put my x values into that formula and use that answer as the x vale for the original formula? Many thanks.
Thanks Ackbeet for the advice, ill remember that one.
ok so ive worked out the volume for the trough is
Volume = 4x3 – 8x2 +4x
[IMG]file:///C:/DOCUME%7E1/LIAMST%7E1/LOCALS%7E1/Temp/msohtmlclip1/01/clip_image002.gif[/IMG]now i have found dy/dx = 12x2 – 8x +4
This has left me with a quadratic so i have put this into the quadratic equation
and have came up with two x answer's these are x=1 and x =0.33
do i put the 0.33 into the orignal equation 4(0.333 )– 8(0.332 )+4(0.33) to find the volume which i worked out as 0.592m2
Or do i have to differentiate the equation again
d2y/dx2 = 24x - 8
and substitue 0.33 into the euqation to give the answer -0.08
and then use this in the original formula 4(-0.083 )– 8(-0.082 )+4(-0.08) = -1.28 m2
thanks for the reply running-gag , im sorry if im a pain for all the replies, but im really new to calculus and im still at secondary schoollearning it so all of these notations and formulas i can find confusing.
could i just check with you that the correct answer for the volume of the trough is 0.592 metres cubed?