Question

Bantu jawab caranya ka​

Answer 1

x di kuadran 1

cos4x=2(cos2x)^2-1=1/3 => cos2x=sqrt(2/3)

cos2x=1-2(sinx)^2=sqrt(2/3) => (sinx)^2=1/2(1-sqrt(2/3))

(secx)^2=1/(sinx)^2=6+2sqrt6

2/(2-(secx)^2)=2/(2-(6+2sqrt6))=1-sqrt(3/2)

(A)