Search found 10 matches

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

Geometry problem

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38284439_476023639539494_8805193864634695680_o.jpg (94.83 KiB) Viewed 3992 times
by mdhasib
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 .
by mdhasib
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
by mdhasib
Mon Jan 09, 2017 12:23 pm
Forum: Secondary Level
Topic: Dhaka regional 16 P4
Replies: 5
Views: 2093

Dhaka regional 16 P4

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by mdhasib
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 :D :D :D :D
by mdhasib
Sun Jan 01, 2017 8:40 am
Forum: Secondary Level
Topic: Dhaka regional 16 P2
Replies: 1
Views: 1143

Dhaka regional 16 P2

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Untitled.png (66 KiB) Viewed 1143 times
by mdhasib
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 ?
by mdhasib
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
by mdhasib
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
by mdhasib
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 ....