Re: DSE 2009

Posted by ritu on Feb 24, 2012; 12:49pm
URL: http://discussion-forum.276.s1.nabble.com/DSE-2009-tp7296495p7314731.html

dse
1.consider the function f mapping points of the plane into the plane,defined by f(x,y)=(x-y,x+y)the range of this function is....
a.the 45 degree line
b.a ray through origin but not the 45 degree line
c.the entire plane
d.the first and third quadrant

i think its c...but i dnt kno if wot i am thinking is correct....x-y and x+y are independent vectors....when we plot f(x,Y) in 2-D space these two will span the entire vector space...
i might be horribly wrong so pls tell me the correct answer...



2.suppose we are interested in estimating the mean height of MA students in delhi university...an average height estimated from a random sample size 30 is better than that estimated from a random sample of size 20 coz....
a.the sample of size 20 is likely to be more biased because its less representative
b.the sample of size 30 is likely to yield more precise estimates of average height than sample size of 20.
c.the central limit theorem prescribes a minimum sample size of 30
d.both a and b..

b and d can be rejected....it may be a or c....wot is the right answer????



3.suppose f:[0,1] to [0,1] is a continuous nondecresing function with f(0)=0 and f(1)=1.define g:[0,1] to [0,1] by g(y)=min{x belongs to [0,1] such that f(x)>=y}.then
a.g is non decreasing
b.if g is continuous,then f is strictly increasing
c.neither a nor b is true
d both a nd b are true
[dse 2010]


kindly help