||
Membaca
SMK Teknologi dan Rekayasa

Soal 92 Koordinat Kutub – Koordinat Kartesius


Koordinat\ kutub\ titik\ A(6,\ 120^{\circ}).\ Koordinat\ kartesiusnya\ adalah\ ....\\a.\ \ (3,\ 3\sqrt{3})\ \ \ \ \ \ \ \ \ \ \ \ b.\ \ (-3,\ -3\sqrt{3})\ \ \ \ \ \ \ \ \ \ \ \ c.\ \ (-3\sqrt{3},\ 3)\\d.\ \ (-3,\ 3\sqrt{3})\ \ \ \ \ \ \ \ \ \ e.\ \ (3\sqrt{3},\ -3)
Jawaban: d

\begin{array}{rcl}Koordinat\ kutub&\rightarrow &Koordinat\ kartesius\\(r,\ \alpha )&\rightarrow &(x,\ y)\end{array}
r=6,\ \ \alpha =120^{\circ}\\(Karena\ \alpha \ sudut\ di\ kuadran\ II,\ maka\ x\ negatif\ dan\ y\ positif)
\begin{array}{rcl}x&=&r\ cos\ \alpha\\&=&6\times cos\ 120^{\circ}\\&=&6\times cos\ (180-60)^{\circ}\\&=&6\times (-cos\ 60^{\circ})\\&=&6\times (-\frac{1}{2})\\&=&-3\end{array}
\begin{array}{rcl}y&=&r\ sin\ \alpha\\&=&6\times sin\ 120^{\circ}\\&=&6\times \ sin\ 60^{\circ}\\&=&6\times \frac{1}{2}\sqrt{3}\\&=&3\sqrt{3}\end{array}
Koordinat\ kartesiusnya\ adalah\ (-3,\ 3\sqrt{3})

About Kalakay

Guru Matematika SMK

Diskusi

Belum ada komentar.

Tinggalkan Balasan

Isikan data di bawah atau klik salah satu ikon untuk log in:

Logo WordPress.com

You are commenting using your WordPress.com account. Logout / Ubah )

Gambar Twitter

You are commenting using your Twitter account. Logout / Ubah )

Foto Facebook

You are commenting using your Facebook account. Logout / Ubah )

Foto Google+

You are commenting using your Google+ account. Logout / Ubah )

Connecting to %s

%d blogger menyukai ini: