计算:sin420度乘cos750度 sin(-330度)乘cos(-660度)-搜答案-搜搜考试网

0.36×（1.5×0.4）＝0.36×0.6＝0.216

0.125x8x4x25再答：等于1x100

0.8×9.58×1.25=0.8×1.25×9.58=1×9.58=9.58希望能解决您的问题.

9.9乘9.9加0.99=99×0.1×99×0.1+99×0.01=99×99×0.01+99×0.01=（99×99+99）×0.01=99×100×0.01=99

0.8*0.3*1.25=0.8*1.25*0.3=1*0.3=0.30.125*8=10.25*4=1这些都要牢记

36分成4和9乘25在乘1036×25×10=4×25×9×10=9000

sin420cos750+sin(-330)cos(-660)=sin(360+60)cos(2*360+30)+sin(-360+30)cos(-2*360+60)=sin60cos30+sin30

(sin7+cos15sin8)/(cos7-sin15sin8)=[sin7+cos(7+8)sin8]/[cos7-sin(7+8)sin8]=[sin7+(cos7cos8-sin7sin8)s

先算0.4乘0.5

1.25x0.7x0.8=1.25x0.8x0.7=1x0.7=0.7再问：谢了

8x1.95x1.25=8x1.25x1.95.乘法交换律=10x1.95=19.5

(sin7+cos15sin8)/(cos7-sin15sin8)=sin(15-8)+cos15sin8)/(cos(15-8)-sin15sin8)=(sin15cos8-cos15sin8+co

如图,打那太吃力了,你才零分能给你这么打不错了.已更新

sin420°乘cos750°＋sin(－330°)乘cos(－660°)乘tan（225°）=sin(360+60)*cos(360*2+30)+sin(360-330)*cos(360*2-660

0.75×32×12.5=(0.75×4)×(8×12.5)=3×100=300

0.375*8*0.75*4*0.1再问：全部的过程！再答：3.2=8*4*0.10.375*0.75*3.2=0.375*8*0.75*4*0.1=3*3*0.1=9*0.1=0.9再问：3.2是啥

设2009=a.则2009×20082008-2007×20092009=a(a-1)×10001-（a-2）a×10001=10001(a^2-a-a^2+2a)=10001a=20092009

cos7π/8=-cos(π-7π/8)=-cosπ/8同理cos5π/8=-cos3π/8又cos3π/8=sin(π/2-3π/8)=sinπ/8所以cosπ/8的四次方+cos3π/8的四次方+