gunakan langkah dan cara

Kode : 10.2.6 [Kelas 10 Matematika Bab 6 - Trigonometri Dasar]

Penyelesaian

[e] Nilai secan sudut di kuadran II
[tex]sec \ \frac{3 \pi }{4} =sec \ ( \pi - \frac{ \pi }{4} ) \\ sec \ \frac{3 \pi }{4} =-sec \ \frac{ \pi }{4} \\ sec \ \frac{3 \pi }{4} =- \frac{1}{cos \ \frac{ \pi }{4} } \\ sec \ \frac{3 \pi }{4} =- \frac{2}{ \sqrt{2} }=- \sqrt{2} [/tex]

[f] Nilai cosecan sudut di kuadran III
[tex]cosec \ 217^0 =cosec \ (180+37)^0 \\ cosec \ 217^0 =-cosec \ 37^0\\ cosec \ 217^0 =- \frac{1}{sin \ 37^0} \\ cosec \ 217^0 =- \frac{5}{3} [/tex]

[g] Nilai cosecan sudut di kuadran III
[tex]cosec \ (-\frac{2 \pi }{3}) =-cosec \ \frac{2 \pi }{3} \\ cosec \ (-\frac{2 \pi }{3}) =-cosec \ ( \pi -\frac{ \pi }{3}) \\ cosec \ (-\frac{2 \pi }{3}) =- \frac{1}{sin \ \frac{ \pi }{3} } \\ cosec \ (-\frac{2 \pi }{3}) =- \frac{2}{ \sqrt{3} }=- \frac{2}{3} \sqrt{3} [/tex]

[h]. Nilai cosinus sudut di kuadran I
[tex]cos \ (-300^0)=+cos \ 300^0 \\ cos \ (-300^0)=cos \ (360-60)^0 \\ cos \ (-300^0)=cos \ 60^0 \\ cos \ (-300^0)= \frac{1}{2} [/tex]