The formula to find mean from a grouped frequency table is . `bar(x) = a + (sumf_(i)u_(i))/(sumf_(i)) xx h`. In the formula, `u_(i)=.........`

For a given frequency distribution, n = 20 and sumf_i x_i = 140, then barx = ..........

If ((1i)^(2))/(2-i)=x+iy , then find the value of x+y.

If ((1+i)^(2))/(2-i)=x+iy then find the value of x+y.

The relative humidity (in %) of a certain City for a September month of 30 days was as follows: (i) Construct a grouped frequency distribution table with classes 84-86, 86,-88 etc. (ii) What is the range of the data?

If sum_(i=1)^(2n)cos^(-1)x_i=0 then find the value of sum_(i=1)^(2n)x_i

The potential energy of 1 kg particle , free to move allong is given by U(x) = ((x^(3))/3-(x^(2))/2) I . if its mechanical energy is 2J . Its maximum speed is …… ms^(-1)

{:("Column I","Column II"),((A)" As object is approaches from x = oo to x = R ,the image approaches the pole . The mirror must be",(p)"convex"),((B)"As object approches from x = R//2 to x=0 , then the image approaches the pole. The mirror may be",(q)" concave"),((C) "The speed of the object is u , then if mirror is concave the speed of the image is " , (r) ((R)/(R + 2x))^(2)u) , ((D) " The speed of the object is u , then if mirror is convex then speed of the image is " , (s) ((R)/(R-2x))^(2)u):}