【求值】tan22.5°⼀(1-tan222.5°)

2024-11-26 01:26:38
推荐回答(2个)
回答1:

tan22.5/(1-tan²22.5)
=[2tan22.5/(1-tan²22.5)]÷2
=tan(22.5×2)÷2
=tan45÷2
=1/2

回答2:

设去年定期x万,活期3000-x万
x(1+25%)+(3000-x)(1-25%)=3000(1+15%)
1.25x+2250-0.75x=3450
0.5x=1200
x=2400
x(1+25%)=3000
(3000-x)(1-25%)=450
答:今年定期3000万,活期450万