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## #1 Help Me ! » Rate of Change » 2011-07-28 14:01:57

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A ladder AB of length 5 has one end A leaning against a vertical wall. The other end B rests on horizontal ground. When A is 4m above the ground, it slides down at 2m/s. How fast does B slide?

woops typo

## #3 Help Me ! » Functions and Relations » 2011-06-29 17:05:07

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Suppose p is an integer such that p≥0 and q is a natural number. It is also defined that p mod q is the remainder when p is divided by q. For example, 4mod4= 0, 7mod4=3, 3mod4=3.

Given that A={0,1,2,3,4} and f:A->A is defined by f(x)=3x mod5.

a)Express the function f as a set of ordered pairs.
b)Find the range of f.
c) Explain whether f^-1 exists or not and find f^-1 if it exists.

## #4 Help Me ! » Pattern problem » 2011-04-06 02:13:55

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What is the 2011th digit of the number sequence 1,4,9,16,25,36,49,64,81,100,121,144.....?

## #5 Help Me ! » Speed Problem » 2011-04-01 02:33:02

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Replies: 7

A man plans on arriving by train at the station at 3:00pm and then plans to have his wife drive him home. Instead, he catches an earlier train and arrives at the station at 2.00pm. He decides to walk toward home and is picked up by his punctual wife en route. They arrive home twenty minutes earlier than planned. How long did he walk?

## #6 Help Me ! » Division problem » 2011-01-21 16:39:13

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Using the numbers 5,6,7,8,9, each once, make a 3 digit number and a 2 digit number that gives a quotient with no remainder. Find 2 pairs, one that gives the biggest quotient and one that gives the lowest quotient.

Is there a analytical way of solving this, or is it just trial and error.

Is this correct?

## #8 Help Me ! » Binomial Theorem » 2010-10-18 02:30:36

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Replies: 4

How do you simplify

## #9 Re: Help Me ! » Plane Geometry » 2010-10-10 02:52:36

why is there an error?

angle ATE = angle TEC (alt angle )
angle ATE = angle ART (alt segment theorem)
angle ART = angle EDT = angle CDT (angle subtended by the same chord)

hence angle TEC = angle EDT

angle TEC = angle TRD (angle subtended by the same chord)
angle EDT = angle ERT (angle subtended by the same chord)

angle TRD = angle TRM, angle ERT = angle ART
hence angle ART = angle TRM

## #10 Re: Help Me ! » Plane Geometry » 2010-10-08 22:08:08

Hi bob bundy;

for (iii), you are proving that ECT is similar to RCD by intercepting chords theorem right?

## #11 Help Me ! » Plane Geometry » 2010-10-07 16:26:38

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Given RD=2MD, 3RE=2RA and ED is parallel to AM,

i) Prove that ΔATE is similar to ΔART
ii) Find area of ΔATE / area of ΔART
iii) Show that ½ RT²= TM x AT
iv) Show that 3AT²=4RD²

e^(lnx) = x

Thanks soroban!

## #14 Help Me ! » how to find minimum value of T » 2010-07-23 01:36:10

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Replies: 3

T>0, 0<x<1200.

How do I find the minimum value of T ?

## #15 Re: Help Me ! » Integration- Trigonometric functions » 2010-07-09 00:20:58

oh. i cant take out unknown... how coicidental. thanks for the help

## #16 Re: Help Me ! » Integration- Trigonometric functions » 2010-07-09 00:09:45

why is it wrong to take out cot²x ?

## #17 Re: Help Me ! » Integration- Trigonometric functions » 2010-07-08 01:28:48

this makes sense to me but i cannot get the negative sign. is there something wrong?

## #18 Re: Help Me ! » Integration- Trigonometric functions » 2010-07-07 01:08:40

what if i am not familiar with d cotx /dx = -csc(x)² ?

## #19 Re: Help Me ! » Integration- Trigonometric functions » 2010-07-06 21:07:32

substitution is the only way?

i was taught to increase the power by 1 and divide by the power+ 1.
can this apply to trig functions too?

why 86?

## #21 Help Me ! » Pattern » 2010-06-14 22:07:27

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Replies: 20

any idea what's the 6th term for 49,54,41,66,25, ___

and if possible the nth term.

## #22 Re: Help Me ! » Integration- Trigonometric functions » 2010-06-14 02:22:06

Is it possible to integrate from here?

## #23 Help Me ! » Integration- Trigonometric functions » 2010-06-13 14:46:25

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Replies: 20

How do you integrate trig functions with fractions??? eg. cosecx or secx

## #24 Re: Help Me ! » Vectors » 2010-05-11 15:56:12

sorry here's the diagram

## #25 Help Me ! » Vectors » 2010-05-11 15:45:42

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OABC is a parallelogram. Line AB is produced to the point D such that AB:BD= 3:2
E is a point on BC such that BE:BC=2:5

OA=p, AB=q

Express in terms of p and/or q,

a) CE
b) OE
d) OD

e) Show that OED is a straight line

f) Find OE:ED

g) The point P lies on AC produced and AP=kAC.

Show that OP=

How to do part g)?