Q75 of 80 Page 239

Choose the correct answer out of 4 options given against each Question

If f(x) = x100 + x99 + … x + 1, then f’(1) is equal to


f(x)=x100 + x99 + ………….x + 1


f'(x) = 100x99 + 99x98 +…… + 1


f'(1) = 100(1)99 + 99(1)98 + …… + 1



[Using Arithmetic Progression, where d = -1, a = 100 & n = 100]


= 50 (200 – 99)


= 50 (101)


= 5050


Hence Option (A) is the correct answer.

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