Question

已知tan

α

2

=2，则tanα的值为______，tan（α+

π

4

）的值为______．

Answer 1

tanα=

2tan α 2

1-tan2 α 2

=

2×2

1-22

=-

4

3

tan（α+

π

4

）=

tanα+1

1-tanα

= -

1

7

．