Question

1+sin^2a=3sina乘以cosa,求tana

Answer 1

3sinacosa=3/2 *(2sinacosa)=3/2*sin2a

即1+sin^2a=3/2*sin2a

解之得 sin2a=1 或 1/2

a=45+2kπ,a=225+2kπ 或a=15+2kπ,a=195+2kπ 或a=75+2kπ a=255+2kπ

tana=1 或tana=2-根号3 或 tana=2+根号3