# Convergence rate estimate of sine and cosine series with $1/k^q$ coefficients

### DOI: 10.31029/demr.7.5

Exact order-of-magnitude estimates of convergence rate of sine and cosine series with coefficients $1/k^q$, $q>1$, are obtained. In case when $0 \le q \le 1$ growth rate exact order-of-magnitude estimates of partial sums of sine and cosine series are proven.

Keywords: sine series, cosine series, lower estimate, convergence rate, growth rate.

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