Объяснение:
1)∠ABM=30°, sin∠ABM=1/2=AM/AB⇒AB=6
BM²=AB²-AM²=36-9=27, BM=3√3
BM=MC=3√3
BC²=BM²+MC²=27+27=54
BC=3√6
2)tg²α+1=1/cos²α. 25/4+1=1/cos²α. 29/4=1/cos²α⇒cos²α=4/29. cosα=2/√29
sin²α=1-cos²α=1-4/29=25/29. sinα=5/√29
ctgα=1/tgα=2/5
Объяснение:
1)∠ABM=30°, sin∠ABM=1/2=AM/AB⇒AB=6
BM²=AB²-AM²=36-9=27, BM=3√3
BM=MC=3√3
BC²=BM²+MC²=27+27=54
BC=3√6
2)tg²α+1=1/cos²α. 25/4+1=1/cos²α. 29/4=1/cos²α⇒cos²α=4/29. cosα=2/√29
sin²α=1-cos²α=1-4/29=25/29. sinα=5/√29
ctgα=1/tgα=2/5