3分之7π怎样算?整道题是cos7π/3+tan(-15π/4),我想要计算过程,还有tan225°×cos240°×sin(-60°）×tan(-30°）

3分之7π怎样算?整道题是cos7π/3+tan(-15π/4),我想要计算过程,还有tan225°×cos240°×sin(-60°）×tan(-30°）
3分之7π怎样算?
整道题是cos7π/3+tan(-15π/4),我想要计算过程,还有tan225°×cos240°×sin(-60°）×tan(-30°）

3分之7π怎样算?整道题是cos7π/3+tan(-15π/4),我想要计算过程,还有tan225°×cos240°×sin(-60°）×tan(-30°）
(1)cos7π/3+tan(-15π/4)
=cos(2π+π/3)+tan(-4π+π/4)
=cosπ/3+tanπ/4
=1/2+1=3/2
(2)tan225°×cos240°×sin(-60°）×tan(-30°）
=tan(180º+45º)×cos(180º+60º)×(-sin60º)×(-tan30º)
=tan45º×(-cos60º)×(-√3/2)(-√3/3)
=1×(-1/2)×1/2=-1/4

第二问：可以把225换为π+45
把240换为π+60

cos7π/3+tan(-15π/4)
= cos(2π+π/3）+ tan(-4π+π/4)
= cosπ/3+ tanπ/4
= 1/2 + 1
= 3/2
tan225°×cos240°×sin(-60°）×tan(-30°）
= tan(180°+45°) × cos(180°+60°) × (-sin60°) × (-tan30°）

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cos7π/3+tan(-15π/4)
= cos(2π+π/3）+ tan(-4π+π/4)
= cosπ/3+ tanπ/4
= 1/2 + 1
= 3/2
tan225°×cos240°×sin(-60°）×tan(-30°）
= tan(180°+45°) × cos(180°+60°) × (-sin60°) × (-tan30°）
= tan45° × (-cos60°) × (-sin60°) × (-tan30°）
= 1 × (-1/2°) × (-√3/2) × (-√3/3）
= - 1/4

收起

1、cos7π/3+tan(-15π/4)
=cos(2π+π/3)+tan(-4π+π/4)
=cosπ/3+tanπ/4
=1/2+1
=1.5
2、tan225°×cos240°×sin(-60°）×tan(-30°）
=tan（180°+45°）×cos（180°+60°）×（-sin60°）×（-tan30°）
=-tan45°×cos60°×sin60°×tan30°