ABCD is a square of length a, `a in N`, a > 1. Let `L_1, L_2 , L_3...` be points on BC such that `BL_1 = L_1 L_2 = L_2 L_3 = .... 1` and `M_1,M_2 , M_3,....`be points on CD such that `CM_1 = M_1M_2= M_2 M_3=... = 1`. Then `sum_(n = 1)^(a-1) ((AL_n)^2 + (L_n M_n)^2)` is equal to :

ABCD is a square of lengths a, a in N, a gt 1 . Let L_(1),L_(2),L_(3) ... Be points BC such that BL_(1) = L_(1)L_(2) = L_(2)L_(3) = ....=1 and M_(1), M_(2), M_(3)... be points on CD such that CM_(1) = M_(1)M_(2) = M_(2)M_(3) = ...=1 .Then, sum_(n= 1)^(a-1)(AL_(n)^(2) + L_(n)M_(n)^(2)) is equal to

A B C is a right-angled triangle in which /_B=90^0 and B C=adot If n points L_1, L_2, ,L_nonA B is divided in n+1 equal parts and L_1M_1, L_2M_2, ,L_n M_n are line segments parallel to B Ca n dM_1, M_2, ,M_n are on A C , then the sum of the lengths of L_1M_1, L_2M_2, ,L_n M_n is (a(n+1))/2 b. (a(n-1))/2 c. (a n)/2 d. none of these

If L_(1) = (2.02 +- 0.01)m and L_(2) = (1.02 +- 0.01)m then L_(1) + 2L_(2) is (in m)

ABC is a right angled triangle in which /_B=90^(@) and BC=a. If n points L_(1),L_(2),"…….",L_(n) on AB are such that AB is divided in n+1 equal parts and L_(1)M_(1),L_(2)M_(2),"......,"L_(n)M_(n) are line segments parallel to BC and M_(1),M_(2),M_(3),"......,"M_(n) are on AC, the sum of the lenghts of L_(1)M_(1),L_(2)M_(2),"......,"L_(n)M_(n) is

If L_(1) = (3.03 +- 0.02)m and L_(2) = (2.01 +- 0.02)m then L_(1) + 2L_(2) in (in m )

For an orbital with n = 2, l = 1, m = 0 there is/are

The direction cosines of the lines bisecting the angle between the line whose direction cosines are l_1, m_1, n_1 and l_2, m_2, n_2 and the angle between these lines is theta , are

Let (l_1,m_1,n_1) and (l_2,m_2,n_2) be d.c's of two lines.Then the lines are parallel if l_1/l_2=m_1/m_2=n_1/n_2 (Prove It)