Page 14 - FIKA SARI FIBRI HASTUTI_MODUL MATEMATIKA KLS X SEM 2

Dengan demikian, diperoleh :

1 √2 √2 1
o
➢ sin 45 = = = × = = √2
√2 √2 √2 2 2
1 √2 √2 1
o
➢ cos 45 = = = × = = √2
√2 √2 √2 2 2
o
➢ tan 45 = = = 1

o
Mengingat kembali Definisi 4.1, terdapat cara lain untuk menentukan nilai tan 45 , yaitu
√2

sin 45
o
tan 45 = = 2 = 1
cos 45 √2
2
o
o
o
Dengan nilai diatas, kita bias menentukan nilai sec 45 , css 45 , dan cot 45
√2
o
➢ sec 45 = = = √2 atau

o
sec 45 = 1 = 1 = 2 × √2 = 2√2 = √2
cos 45 √2 √2 √2 2
2

o
➢ csc 45 = = √2 = √2 atau

o
csc 45 = 1 = 1 = 2 × √2 = 2√2 = √2
sin 45 √2 √2 √2 2
2
1 1
o
o
➢ cot 45 = = = 1 atau cot 45 = = = 1
tan 45 1

Jadi, dapat disimpulkan

1 o 1 o
o
sin 45 = √2 cos 45 = √2 tan 45 = 1
2
2
o
o
o
csc 45 = √2 sec 45 = √2 cot 45 = 1

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