作业帮cos83°·cos23°+sin83°·sin23°=
来源：学生作业帮助网 编辑：作业帮 时间：2024/11/15 01:54:53
cos83°·cos23°+sin83°·sin23°=
cos83°·cos23°+sin83°·sin23°=
cos83°·cos23°+sin83°·sin23°=
原式=1/2
∵由公式：cos(α-β) = cosαcosβ + sinαsinβ
∴cos83°·cos23°+sin83°·sin23° = cos(83° - 23°) = cos60° = 1/2
cos83°·cos23°+sin83°·sin23°=cos﹙83-23﹚º=cos60º=0.5
cos83°·cos23°+sin83°·sin23°=
那位大哥帮帮忙～化简计算：cos23°cos83°＋cos67°sin83°＝＿
sin37°cos83°+cos37°sin83°
为什么sin83°=cos7°
sin7°cos37°－sin83°cos307°=
化简:cos83°+sin75°sin8°/cos7°-cos75°cos82°
cos23°cos22°-sin23°sin22°=
cos22°cos23°-sin22°sin23°等于
sin23°cos68°-cos23°sin68°的值
求值sin68°cos23°-cos68°sin23°=
计算：cos23°cos22°-cos67°cos68°
cos7°cos23°-sin7°sin23°=?
请问sin23°,cos23°,tan23°分别等于多少?
sin7°cos37°—sin83°cos53°的值是?谢谢
sin7°cos37°-sin83°sin37°的值是多少?3Q
sin7°cos37°－sin83°cos307° 求过程!
sin7°cos37°-sin83°cos307°化简求值 求详细过程
sin53°cos83°-cos53°sin97°要过程主要问sin97°怎么化成83°