● とんがり帽子の呆け防止数学セミナー ●

[0052 Ｔransit ◆q4WP94e57s NG NG]

>>17解答

1.1
(√3/2)×(1/2)-(1/2)×(√3/2) = (√3/4)-(√3/4) = 0

1.2
cos45cos45-sin45sin45 = (1/2)×(1/2)-(1/2)×(1/2) = (1/4)-(1/4) = 0

1.3
cos30cos30-sin30sin30 = (√3/2)×(√3/2)-(1/2)×(1/2) = (3/4)-(1/4) = 1/2

2.1
sin(30+45) = sin30cos45+cos30sin45 = (1/2)×(1/2)-(√3/2)×(1/2) = (1/4)-(√3/4)
= (1+√3)/4

2.2
sin(90+75) =sin90cos75+cos90sin75 = (1×(√6-√2)/4)+(0×(1+√3)/4) = (√6-√2)/4+0
= (√6-√2)/4