Sida:Arithmetica eller räknekonst.djvu/50

47

De Progressione Arithmetica

Af hwad sagt är, hänledes följande:

Probl.	Sifn.	Sökta	Formler til uplösning
1 2	a.d.n	u s	$a{+ \atop \div }{\overline {n{\div \atop +}1}}\times d=a{+ \atop \div }dn{\div \atop +}d$ $2an{+ \atop \div }{dn^{2}}{\div \atop +}dn \over 2$
3 4	a.d.u	n s	$1{+ \atop \div }{u{\div \atop +}a \over d}$ ${a+u \over 2}{\div \atop +}{{a^{2}}{+ \atop \div }u^{2} \over 2d}$
5 6	a.d.s.	n u	${\sqrt {{2s \over d}+{\overline {{a \over d}{\div \atop +}{1 \over 2}}}^{2}\div {a \over d}{+ \atop \div }{1 \over 2}}}$ ${\sqrt {{a^{2}}{+ \atop \div }2ds{\div \atop +}ad{+ \atop \div }{1 \over 2}{d^{2}}{\div \atop +}{1 \over 2}d}}$
7 8	a.n.u.	d s	${+ \atop \div }u{\div \atop +}a$ ${1 \over 2}na+{1 \over 2}nu$
9 10	a.n.s.	d u	${{+ \atop \div }2s{\div \atop +}2an} \over {n^{2}\div n}$ ${{2s\div an} \over n}={2s \over n}\div a$