My thread of questions

[VeryCrazyEdu.]

oh really? wow thanks for that! saves me some time.. i'm afraid then i probably can't help you! im not very good with latex

[jaja]

Insight 2008, Mc Q3)......

"the number of solutions to the equation (X^2 - a) (x^3 - b^3) (X + c)=0  where a,b,c is an element of R+....

the ans is 4.. however why?

when solving for x wouldn't  X = plus or minus square root of a??? wouldn't we ignore the - since "a in an element of R+??? this goes the same for when X = -c

[TrueTears]

Insight 2008, Mc Q3)......

"the number of solutions to the equation (X^2 - a) (x^3 - b^3) (X + c)=0  where a,b,c is an element of R+....

the ans is 4.. however why?

when solving for x wouldn't  X = plus or minus square root of a??? wouldn't we ignore the - since "a in an element of R+??? this goes the same for when X = -c

would have 2 solutions.

which would have 1 solution.

would have 1 solution

Total number of solutions: 4

[ngRISING]

bah. =S . need help with this question, one of the ones i got wrong in my prac exams.

[TrueTears]

You just try to find no?

[ngRISING]

yeah, but not sure where i went wrong, need someone to diff it so i can compare lol .

[TrueTears]

[ngRISING]

ty ty

[jaja]

Insight 2008, Mc Q3)......

"the number of solutions to the equation (X^2 - a) (x^3 - b^3) (X + c)=0  where a,b,c is an element of R+....

the ans is 4.. however why?

when solving for x wouldn't  X = plus or minus square root of a??? wouldn't we ignore the - since "a in an element of R+??? this goes the same for when X = -c

would have 2 solutions.

which would have 1 solution.

would have 1 solution

Total number of solutions: 4

i get that part.. but the question states "where a,b,c are elements of R+.... All pOSITIVE REAl NUMBERS......

[Mao]

a, b, c are all positive real numbers, but that does not place any restrictions on the roots (i.e. x can still be anything)

Hence, there are 4 roots as shown by TT.

[jaja]

ahh thx.. got it now!

[jaja]

2008 Insight exam short question Q2e?? anyone???.. also Q 2f

also in VCCA sample exam 1, 2006; Q2a... when it asks to differentiate 3x^4 (times) tan(x)........would we lose marks if we just left it like.................3x^3 (4tanx + 3x/(cosx)^2)

6b)....find Pr (X<0.5)... since its a probability density function when finding the answer, can the answer be  in units square, since its the area?

Q8c) if question states find "an- anti- derivative" does that mean C can be any value?

[TonyHem]

?
Q8c) if question states find "an- anti- derivative" does that mean C can be any value?

http://vcenotes.com/forum/index.php/topic,17530.0.html

and for the derivative question, you made a mistake but that form is fine unless you mean whether you have to fully simplify - which is most likely unless its like a 1 mark q.

[dcc]

6b)....find Pr (X<0.5)... since its a probability density function when finding the answer, can the answer be  in units square, since its the area?

I don't have the question your asking, but if it's asking for a probability, it just means a unitless number in between 0 and 1 (inclusive).  While the concept of 'area under the curve' is useful for understanding some of the properties of integrals, it doesn't always work the other way (i.e. an integral isn't necessarily an area)

[jaja]

ahhh got it, thx mate!