Question
What is the value of 1² + 3² + 5² + 7² + 9²
................ 19²?Solution
Sum of the squares of odd number = (n(n+1)(n+2))/6 Where n = Last term = (19×20×21)/6 = 1330 type-2 Sum of the squares of odd number = (n(2n+1) (2n-1))/3 Where n = (Last term+1)/2= (19+1)/2=10 = (10×21×19)/3 = 1330
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