sin(90°-x)=²／³x=?

sin(90°-x)=²／³
x=?

sin(90°-x)=cosx=²／³
cos48°47ˊ=2/3
x=48°47ˊ.

cosx=2/3，取反函数就算出来了

sin(90°-x)=²／³
cosx=2/3
x=arccos2/3