The value of `sum_(r=1)^(15)(r2^r)/((r+2)!)` is (a).`((17)!-2^16)/((17)!)` (b). `((18)!-2^(17))/((18)!)` (c). `((16)!-2^(15))/((16)!)` (d). `((15)!-2^(14))/((15)!)`

The value of sum_(r=1)^(15) (r2^(r))/((r+2)!) is equal to (a) ((17)!-2^(16))/((17)!) (b) ((18)!2^(17))/((18)!) (c) ((16)!-2^(15))/((16)!) (d) ((15)!-2^(14))/((15)!)

The value of sum_(r=1)^oocot^(- 1)((r^2)/2+15/8) is equal to

The value of sum_(r=0)^(10)(r)^(20)C_r is equal to: a. 20(2^(18)+^(19)C_(10)) b. 10(2^(18)+^(19)C_(10)) c. 20(2^(18)+^(19)C_(11)) d. 10(2^(18)+^(19)C_(11))

The value of sum_(r=0)^(15)r^(2)((""^(15)C_(r))/(""^(15)C_(r-1))) is equal to

The value sum_(r=0)^(7)tan^(2)""(pix)/(16) is equal to :

The value of sum_(r = 1)^15 r^2 ((""^15C_r)/(""^15C_(r - 1)) ) of is equal to

If ((n),(r )) "denotes " ""^nC_r then (a) Evalutae : 2^(15)((30),(0))((30),(1))-2^(14)((30),(1))((29),(14))+2^(13)((30),(2))((28),(13)).......-((30),(15))((15),(0)) ( b) Prove that : Sigma_(r=1)^(n) ((n-1),(n-r))((n),(r))=((2n-1),(n-1)) ( c) Prove that : ((n),(r))((r),(k))=((n),(k))((n-r),(r-k))

Prove that cos((2pi)/(15))cos((4pi)/(15))cos((8pi)/(15))cos((16pi)/(15))=1/(16)

i^(14)+i^(15)+i^(16)+i^(17)=

Prove that cos((2pi)/(15))cos((4pi)/(15))cos((8pi)/(15))cos((14pi)/(15))=1/(16)