Co-aontaran triantanachd anns a bheil ceàrnan fà-fhillte (leudachadh)
Eisimpleir
Fuasgail an co-aontar \(5\cos (6x - 20)^\circ + 3 = 7.25\), airson \(0 \le x \le 180\).
Fuasgladh
\(5\cos (6x - 20)^\circ + 3 = 7.25\)
\(5\cos (6x - 20) = 4.25\)
\(\cos (6x - 20) = 0.85\)
Bhon a tha cos dearbhte, tha sinn sa 1d agus sa 4mh cairteal.
A' chiad chairteal
\(6x - 20 = 31.8^\circ\)
\(6x = 51.8^\circ\)
\(x = 8.6^\circ\)
An ceathramh cairteal
\(6x - 20 = 360^\circ - 31.8^\circ\)
\(6x - 20 = 328.2^\circ\)
\(6x = 348.2^\circ\)
\(x = 58.0^\circ\)
Bhon a tha \(0 \le x \le 180\), feumaidh sinn na toraidhean eile a lorg le bhith a' cur na peiriad ris na fuasglaidhean seo.
\(Peiriad = 360^\circ \div 6 = 60^\circ\)
3mh fuasgladh: \(8.6 + 60 = 68.6^\circ\)
4mh fuasgladh: \(58.0 + 60 = 118^\circ\)
5mh fuasgladh: \(68.6 + 60 = 128.6^\circ\)
6mh fuasgladh: \(118 + 60 = 178^\circ\)
7mh fuasgladh: \(128.6 + 60 = 188.6^\circ\). Chan e fuasgladh a tha seo bhon a tha \(0 \le x \le 180\).
Mar sin \(x^\circ = 8.6^\circ ,\,58^\circ ,\,68.6^\circ ,\,118^\circ,\,128.6^\circ,\,178^\circ,\,188.6^\circ\)
