@adityaknsit said:thanks for clearing it up man....the range of 1/(5sin(x + y) + 3) comes out to be -1/2 to infinity, then...isn't?
right ... sorry abt dat.
@albiesriram said:x=>1803Cos180 = -3sin 180 =0so (3+3cosx+4sinx) =0y=>infi
right..right.. didnt see dat.
[-0.5 to infinity ]
@adityaknsit said:thanks for clearing it up man....I think the lower limit is fine, but the upper limit should be infinity....if sin(x + y)=-3/5......the denominator will turn 0 and hence the expression would be infinity
right.. dint see that. thnx. 
@anitito123
Shld be 17^105..
Here, AM>=GM
=>(17^105 + 31^84)/2 > (17^105*31^84)^(1/2)
=>17^105 + 31^84 > 2*_/17^105*_/31^42
=>(17^52)^2*(_/17)^2 + (31^42)^2 > 2*17^52*_/17*31^42
=>(17^52)^2*(_/17)^2 + (31^42)^2 - 2*17^52*_/17*31^42 > 0
=>[(17^52)*(_/17) - (31^42) ]^2 > 0
=>(17^52)^(_/17) > 31^42
=> 17^105 > 31^84 [After Squaring both sides]..
If x% of y is 1% of z,y% of z is 1% of x, z% of x is 1% of y,then find the value of xy+yz+zx.
options:1,2,3,4
@anitito123 said:If x% of y is 1% of z,y% of z is 1% of x, z% of x is 1% of y,then find the value of xy+yz+zx.options:1,2,3,4
-1,0,3
@Estallar12 Hello, how are you doing. Its been a long time now. Hope all is well. College is keeping me busy
if.....x% of y is 1% of z
therefore, xy=z
similarly yz=x
and zx=y
so, x,y,z=(0,0,0).....(1,1,1)......(-1,-1,1) (-1,1,-1)(1,-1,-1)......so....putting each of these sets in xy+yz+zx we get three values.....-1,0,3
therefore, xy=z
similarly yz=x
and zx=y
so, x,y,z=(0,0,0).....(1,1,1)......(-1,-1,1) (-1,1,-1)(1,-1,-1)......so....putting each of these sets in xy+yz+zx we get three values.....-1,0,3
@anitito123 said:If x% of y is 1% of z,y% of z is 1% of x, z% of x is 1% of y,then find the value of xy+yz+zx.options:1,2,3,4
If I assume that we are taking about +ive percentages then the answer is 3
as we get xy=z,yz=x,zx=y and xy+yz+zx=x+y+z=>x=y=z=1
as we get xy=z,yz=x,zx=y and xy+yz+zx=x+y+z=>x=y=z=1
the sum of the reciprocals of the positive divisors of 120 ?
options:2,3,4,6
Plz mention the approach.
A boat takes a total of 5 hrs to make a round trip btwn 2 points in a river which is 24 Km apart.Had the speed of the boat tripled, the boat wud had taken a total of 7.5 Hrs to make the same trip. Find the speed of the boat in still water. 
@anitito123 said:the sum of the reciprocals of the positive divisors of 120 ?options:2,3,4,6Plz mention the approach.
it wld be simply (sum of factors)/120....
120 = 5*2*3*2^2 = 2^3*3*5
sum of factors = (2^0+2^1+2^2+2^3)(3^0+3^1)(5^0+5^1) = 360
hence, asnwer = 360/120 = 3
@anitito123 said:the sum of the reciprocals of the positive divisors of 120 ?options:2,3,4,6Plz mention the approach.
It would Just be the sum of factors divided by the number . ((1+2+4+8)*(1+3)*(1+5))/120 = 360/120 = 3 !!
@anitito123 120 = 2^3 * 3 * 5
Sum of its factors = (1 + 2 + 4 + 8)(1 + 3)(1 + 5) = 360
Sum of the reciprocals of its factors = 360 / 120 = 3
For any number N = a^p*b^q*c^r
Sum of its factors = (1 + a + a^2...a^p)(1 + b + b^2...b^q)(1 + c + c^2...c^r)
Sum of the reciprocal of its factors
= (1 + a + a^2...a^p)(1 + b + b^2...b^q)(1 + c + c^2...c^r) / N
@pyashraj said:A boat takes a total of 5 hrs to make a round trip btwn 2 points in a river which is 24 Km apart.Had the speed of the boat tripled, the boat wud had taken a total of 7.5 Hrs to make the same trip. Find the speed of the boat in still water.
When the speed of the boat is increasing, how is the time taken getting increased??