Question

sin53°cos83°-cos53°sin97°要过程

主要问sin97°怎么化成83°

Answer 1

公式sinAcosB-cosAsinB=sin(A-B)=sin(53-83)= - 1/2
画坐标图，sin83=sin97
用公式 sin(A)=sin(pai-A)

Answer 2

sin53cos83-cos53sin97
=sin53cos(90-7)-cos53sin(90+7)
=sin53(cos90cos7+sin90sin7)-cos53(sin90cos7+cos90sin7)
=(sin53cos90-cos53sin90)cos7-(cos53cos90-sin53sin90)sin7
=sin(53-90)cos7-cos(90+53)sin7
=-sin37cos7+cos(180-37)sin7
=-(sin37cos7-cos37sin7)
=-sin(37-7)
=-sin30
=-1/2

Answer 3

sin53°cos83°-cos53°sin97°
=sin53°cos83°-cos53°sin83°
=sin(53°-83°)
=sin(-30°)
=-sin30°
=-1/2

Answer 4

sin53°cos83°-cos53°sin97°
=sin53°cos83°-cos53°sin83°
=sin（53°-83°）=-sin30°=-1/2

Answer 5

谢谢sin7°cos37°—sin83°cos53° =sin7°cos37°-cos7°sin37° =sin(7°-37°) =sin(-30) =-1/2 1