令r=htant,原式=∫ 1/(h²tan²t+h²)^(3/2) d(htant)
=(1/h²)∫cost dt=(1/h²)sint+C
tant=r/h
sint=cost*tant=tant/sect=tant/√(1+tan²t)=r/√(h²+r²) + C
故结果为r/[h²√(h²+r²)] + C
令r=htant,原式=∫ 1/(h²tan²t+h²)^(3/2) d(htant)
=(1/h²)∫cost dt=(1/h²)sint+C
tant=r/h
sint=cost*tant=tant/sect=tant/√(1+tan²t)=r/√(h²+r²) + C
故结果为r/[h²√(h²+r²)] + C