Ag ath-òrdachadh co-aontar
Airson an caiseadAir graf, 's e an caisead claonadh na loidhne. Mar as motha an caisead, 's ann as motha a tha reat an atharrachaidh. agus an trasnadh-y a dhèanamh a-mach bho cho-aontar loidhne dhìreach nach eil san òrdugh cheart, feumaidh sinn an co-aontar ath-òrdachadh an toiseach.
Eisimpleir
Obraich a-mach an caisead aig an trasnadh-y aig loidhne dhìreach le co-aontar \(2x + y - 13 = 0\).
Ath-òrdaich an co-aontar dhan riochd \(y = mx + c\) a' cleachdadh nan riaghailtean bunaiteach ailseabrach airson co-aontaran fhuasgladh.
\(2x + y - 13 = 0\)
\(2x + y = 0 + 13\)
\(y = 13 - 2x\)
\(y = - 2x + 13\)
Mar sin 's e an caisead \(m = - 2\)
agus an trasnadh-y: \(c = 13\, \to (0,13)\)
Feuch a-nis a' cheist gu h-ìosal.
Question
Obraich a-mach caisead na loidhne le co-aontar \(2x + 5y - 6 = 0\)
Ath-òrdaich seo dhan riochd \(y = mx + c\) gus am faigh thu:
\(2x + 5y - 6 = 0\)
\(5y = - 2x + 6\)
\(y = - \frac{2}{5}x + \frac{6}{5}\)
\(caisead = - \frac{2}{5}\)
Question
Obraich a-mach caisead agus trasnadh-y na loidhne le co-aontar:
\(2y - 5x = 12\).
Ath-òrdaich an co-aontar:
\(2y - 5x = 12\)
\(2y = 12 + 5x\)
\(2y = 5x + 12\)
\(y = \frac{5}{2}x + 6\)
Mar sin \(m = \frac{5}{2}\)
trasnadh-y: \(c = 6 \to (0,6)\)
Comharradh fuincseanach
Faodaidh sinn cuideachd co-aontar loidhne dhìreach a sgrìobhadh san riochd \(f(x) = mx + c\).
Canar comharradh fuincseanach ris an seo. Sin dìreach dòigh eile air an dàimh eadar dà chaochladair a shealltainn.
Mar sin, sa chumantas tha \(y = f(x)\).
Eisimpleir
Ma tha \(f(x)=4x+1\), obraich a-mach \(f(3)\)
Feuch a-nis a' cheist gu h-ìosal.
Freagairt
Tha \(f(3)\) a' ciallachadh gum bi thu ag ionadachadh \(x=3\) gu \(4x+1\)
\(f(3)=4(3)+1\)
\(=12+1\)
= \(13\)
Question
Ma tha \(f(x) = 3x - 5\), obraich a-mach \(f( - 2)\).
Tha \(f( - 2)\) a' ciallachadh gum bi thu ag ionadachadh \(x = - 2\)
\(f(x) = 3x - 5\)
\(f( - 2) = 3( - 2) - 5 = - 6 - 5 = - 11\)
