抱歉,确实错了.
a=arcsin(-1/3)=-arcsin(1/3) 是负锐角,
b=arccos(-2√2/3)=π-arccos(2√2/3)是钝角
c=arctan(-√2/4)=-arctan(√2/4)是负锐角
∵ c=-arctan(√2/4)=-arcsin(1/3)=a
∴ a=c
抱歉,确实错了.
a=arcsin(-1/3)=-arcsin(1/3) 是负锐角,
b=arccos(-2√2/3)=π-arccos(2√2/3)是钝角
c=arctan(-√2/4)=-arctan(√2/4)是负锐角
∵ c=-arctan(√2/4)=-arcsin(1/3)=a
∴ a=c