Quiz Matematika Kelas X SMA Bab Trigonometri

sinx = k

1 - tan²x / 1 + tan²x

= 1 - sin²x/cos²x / sec²x

= (cos²x - sin²x / cos²x) / (1/cos²x)

= cos²x - sin²x / 1

= 1 - 2sin²x

= 1 - 2 (sinx)²

= 1 - 2 k²

Bab Trigonometri
Matematika SMA Kelas X

x = p
Sin p = k = k/1 = y/r
x = √(r² - y²)
x = √(1 - k²)

tan² p = (y/x)²
tan² p = (k/(√(1 - k²)))²
tan² p = k² / (1 - k²)

(1 - tan² p) : (1 + tan² p)
= (1 - (k² / (1 - k²))) : (1 + (k² / (1 - k²)))
= ((1 - k² - k²)/(1 - k²)) : ((1 - k² + k²)/(1 - k²))
✩✩ coret (1 - k²) ✩✩
= 1 - 2k²

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