Question

Guyyss tolong jawab nomer 26 .pake cara ya !!!!

Answer 1

Cosx - sinx = k
(cosx - sinx)² = k²
(cosx - sinx)(cosx - sinx) = k²
(cosx)(cosx) + (cosx)(-sinx) + (-sinx)(cosx) + (-sinx)(-sinx) = k²
cos²x - 2cosxsinx + sin²x = k²
cos²x + sin²x - 2cosxsinx = k²
1 - 2cosxsinx = k²
1 - (sin(x+x) - sin(x-x)) = k²
1 - (sin2x - sin0) = k²
1 - (sin2x - 0) = k²
1 - sin2x = k²
sin2x = 1 - k²

sin = depan / miring

depan = 1 - k²
miring = 1
samping = √1² - (1-k²)²
= √1 - (1 - 2k² + k⁴
= √2k² - k⁴

cos2x = samping / miring
= √2k² - k⁴ / 1
= √2k² - k⁴
= √k²(2 - k²
= √k² . √2-k²
= k√2-k²