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## Search found 10 matches

- Mon Aug 20, 2018 11:59 am
- Forum: Higher Secondary Level
- Topic: Geometry problem
- Replies:
**0** - Views:
**3992**

- Wed Jan 11, 2017 4:52 pm
- Forum: Algebra
- Topic: 2015 regional Secondary no. 6 function algebra
- Replies:
**4** - Views:
**1851**

### Re: 2015 regional Secondary no. 6 function algebra

thank you for pointing out my mistakes asif vai though i can not edit it . But i was trying to mean

**f(x)**by**F(x)**and i didnt think of it as a problem and by the next statement i meant**f(5^k)=((5^k)*(2^(k-2)))+2^(k-3)**. I didnt mention it because it would look hideous .- Mon Jan 09, 2017 1:15 pm
- Forum: Divisional Math Olympiad
- Topic: Dhaka regional higher secondary/8
- Replies:
**3** - Views:
**1926**

### Re: Dhaka regional higher secondary/8

I think

**F(2015)=420**. Because**F(5*384)=F(1920)=420=F(5)+F(384)=F(5)**and**F(384)=0**because 5 does not divide 384 . So**F(2015)=F(5*13*31)=F(5)+F(13)+F(31)=F(5)=420**- Mon Jan 09, 2017 12:23 pm
- Forum: Secondary Level
- Topic: Dhaka regional 16 P4
- Replies:
**5** - Views:
**2093**

- Mon Jan 09, 2017 12:04 pm
- Forum: Algebra
- Topic: 2015 regional Secondary no. 6 function algebra
- Replies:
**4** - Views:
**1851**

### Re: 2015 regional Secondary no. 6 function algebra

Suppose

**F(x)=ax+b**, then**F(F(x))=(a^2)x+ab+b**if we compare**4x+3**with**(a^2)x+ab+b**then we will get**F(x)=2x+1**or**F(x)=-2x-3**Considering the next statement we can be sure that**F(x)=2x+1**.Hence**F(2015)=(2*2015)+1=4031**- Sun Jan 01, 2017 8:40 am
- Forum: Secondary Level
- Topic: Dhaka regional 16 P2
- Replies:
**1** - Views:
**1143**

- Sat Dec 03, 2016 10:22 am
- Forum: Physics
- Topic: height of a well
- Replies:
**1** - Views:
**1282**

### Re: height of a well

Is the answer

**approximately 29.8369 m**?- Mon Aug 01, 2016 9:38 am
- Forum: Secondary: Solved
- Topic: Dhaka Secondary 2009/12
- Replies:
**3** - Views:
**3809**

### Re: Dhaka Secondary 2009/12

Look carefully

**triangle AEF**and**triangle FGD**are similar and**AF/DF =1/3**so**DG=3AE=3**and then we can use Pythagoras and obtain the value of the hypotenuse and the**triangle EFG**is right so the so answer would be half the value of the hypotenuse- Mon Jul 25, 2016 11:31 pm
- Forum: Secondary Level
- Topic: An Easy Geometry Problem
- Replies:
**2** - Views:
**1590**

### Re: An Easy Geometry Problem

The answer is 2 . The area of the base of the pyramid or the equilateral triangle is

**3 square root /2**and the length of the altitude from the top of the pyramid is**2/3 square root**hence the volume must be**1/3**and**3-1=2**- Fri Jul 22, 2016 12:47 pm
- Forum: Secondary: Solved
- Topic: Dhaka Secondary 2009/8
- Replies:
**8** - Views:
**5575**

### Re: Dhaka Secondary 2009/8

We can easily show that triangle FCD and triangle EDB are similar . So FD/DE = CD/BD = FC/BE . Again we can see that triangle FCD and triangle BCD are similar . Again FD/CD = CD/BD = FC/BC .If we merge the conclusions we get FD/CD = FC/BC = FD/DE = CD/BD = FC/BE . We have FC/BC = FC/BE hence BC=BE ....