If AB⊥BC, then the value of k is if A(k,1,−1), B(2k,0,2), C(2+2k,k,1)
Find the values of k, if the points A(k+1, 2k), B(3k, 2k+3) and C(5k-1, 5k) are collinear.
Let a0=52 and ak=a2k−1−2 for k≥1, then the value of ∞Πk=0(1−1ak) is