Section I: Multiple Choice (1 Viewer)

DanS

Born to do better.
Joined
Oct 19, 2013
Messages
119
Location
##CENSORED##
Gender
Male
HSC
2014
Great. All right, I think, except for 2. I changed it from B to C, DON'T ASK. If only we didn't have a 15min blackout halfway thru...

a
c
d
c
b
d
c
c
a
d
 

cafe_pink

New Member
Joined
Mar 3, 2013
Messages
1
Gender
Female
HSC
2014
question 7 is b since tan(pi/2) doesn't exist if you sub it back into the equation
 

vaimvaelk

New Member
Joined
Jun 17, 2013
Messages
3
Gender
Male
HSC
2014
tanx -2 has 2 solutions in 2nd and 4th quadrant while sinx only has one answer pi/2 therefore 3
There are actually only 2 solutions, since when you sub pi/2 into the equation, you get no solution. This is because tan(pi/2) does not exist (sub tan(pi/2) in your calculator and you will get math error).
 

onlyhereforestiamte

New Member
Joined
Jun 8, 2014
Messages
7
Gender
Undisclosed
HSC
N/A
Why do you need to tan (pi/2)? It was just inverse tan -2, which has two solutions
plus 1 solution for sine (pi/2)

Tan(pi/2) is undefined though, the tan curve
you get the pi/2 from the (sinx - 1) bracket, but in the end it doesnt matter since its undefined in the tan curve
oh well woops my bad LOL didnt bother checking like i usually do ^_^
 

Chocolatebubble

Active Member
Joined
Sep 13, 2012
Messages
157
Location
Sydney, Australia, Australia
Gender
Female
HSC
2014
Uni Grad
2019
There are actually only 2 solutions, since when you sub pi/2 into the equation, you get no solution. This is because tan(pi/2) does not exist (sub tan(pi/2) in your calculator and you will get math error).
9/10 my streak has ended :(

funny story, I originally thought tan had no solutions and sin had 2 so b was going to be my answer. and i realise i'm wrong with both my assumptions

yis im gud at meth
 

photastic

Well-Known Member
Joined
Feb 11, 2013
Messages
1,848
Gender
Male
HSC
2014
9/10 my streak has ended :(

funny story, I originally thought tan had no solutions and sin had 2 so b was going to be my answer. and i realise i'm wrong with both my assumptions

yis im gud at meth
But wolfram alpha says 3 solutions. If not, draw the diagram between 0 and 2pie and you will see 3 roots.
 

trungduong12

Active Member
Joined
May 8, 2014
Messages
543
Gender
Male
HSC
2014
Some ppl got D for q5
XD

And everyone argues about q7 :/


Sent from my iPhone using Tapatalk
 

chrisdelinet

Member
Joined
May 6, 2014
Messages
44
Gender
Male
HSC
2014
But wolfram alpha says 3 solutions. If not, draw the diagram between 0 and 2pie and you will see 3 roots.
well if you were to draw the graph you'll plug in pi/2, you get an undefined y value. therefore i presumed those straight line sections are in fact asymptotes. therefore thats why i put 2 solutions.... quite worried for this as it is one of the two marks that are ambiguous with me.
 

chrisdelinet

Member
Joined
May 6, 2014
Messages
44
Gender
Male
HSC
2014
If 7 is C then i lost 2 marks for MC
if 7 is B then GG another mark gone :/




Sent from my iPhone using Tapatalk
problem is it all rides on this one and another answer (depending if they can read my writing) that will determine if i get 97-98 or 98-99, hopefully 7 is b and im in a real chance to get state rank
 

photastic

Well-Known Member
Joined
Feb 11, 2013
Messages
1,848
Gender
Male
HSC
2014
well if you were to draw the graph you'll plug in pi/2, you get an undefined y value. therefore i presumed those straight line sections are in fact asymptotes. therefore thats why i put 2 solutions.... quite worried for this as it is one of the two marks that are ambiguous with me.
The picture clearly shows 3 x intercepts, between 0 and 2pie, hence 3 solutions.

 

chrisdelinet

Member
Joined
May 6, 2014
Messages
44
Gender
Male
HSC
2014
for fuck sakes, i did not see that coming, that nails the bloody cover on the coffin, it must be 3...

i put 3 initially but then was like tanpi/2 is undefined, i freaking hate multiple choice now.
 

photastic

Well-Known Member
Joined
Feb 11, 2013
Messages
1,848
Gender
Male
HSC
2014
for fuck sakes, i did not see that coming, that nails the bloody cover on the coffin, it must be 3...

i put 3 initially but then was like tanpi/2 is undefined, i freaking hate multiple choice now.
No, there is a chance at pi/2 there is an open circle, hence B would be the answer in this case.
 

Users Who Are Viewing This Thread (Users: 0, Guests: 1)

Top