ATAR Notes: Forum

VCE Stuff => VCE Mathematics => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Specialist Mathematics => Topic started by: fredrick on September 30, 2008, 02:05:04 pm

Title: Area under curve
Post by: fredrick on September 30, 2008, 02:05:04 pm: the area enclosed by the graph of $y=\frac{1}{x^2-4x}$ , the x axis and the lines x=1 and x=3 is given by $aloge(b)$ square units where a and b are positive constants. Find a and b.

my answers:
$a=\frac{1}{2}$
$b=3$

the answers they provide is $a=\frac{1}{4}$ and $b=9$
im assuming there are an infinite number of a and b but i provided the simplest form so?
Title: Re: Area under curve
Post by: humph on September 30, 2008, 02:31:05 pm: Yeah, your answer seems better in that it is the simplest form. Was it a multiple choice question? Otherwise they ought to accept your answer.
Title: Re: Area under curve
Post by: fredrick on September 30, 2008, 02:43:06 pm: thanks, nope not a multiple choice.
Title: Re: Area under curve
Post by: xox.happy1.xox on September 30, 2008, 09:19:59 pm: I reckon your answer is indeed correct!
Title: Re: Area under curve
Post by: Collin Li on September 30, 2008, 09:25:11 pm: $\frac{1}{4}\log_e9 = \frac{1}{2}\log_e3$