巧用等比数列求和公式解题河北省万全县教育局高月梅我们知道，等比数列求和公式在解题中有着广泛的应用，诸如有关数列的求和、求极限、证明恒等式等，这方面已有很多文章论及．事实上，等比数列求和公式并不局限于“数列”这一章节，正用、逆用、变形用以及跨学科横向应... Cleverly solving the problem by using the geometric sum formula of equal number series Gao Yuemei, Bureau of Education, Wanquan County, Hebei Province We know that the geometric sum formula has many applications in solving problems, such as summation of numbers, seeking the limit, proving identities, etc. There have been many articles on the issue. In fact, the formula for summation of geometric progression is not limited to the chapter of “series”. It should be used, reversed, deformed and cross-disciplined.