Question

高一数学难题解答

已知tana/tana-1=-1,求sin的平方a+sinacosa+2的值.

Answer 1

tana=1-tana
tana=1/2

sin²a+sinacosa+2
=(sin²a+sinacosa)/(sin²a+cos²a)+2
=(tan²a+tana)/(tan²a+1)+2
=(1/4+1/2)/(1/4+1)+2
=3/5+2
=13/5