Question

If tan thita =20/21,show that (1-sin thita + cos thita) /1+sin thita + cos thita) =3/7​

Answer 1

Tan theta = 20/21

Tan theta = p/b = 20/21

Sin theta = p/h

By pythagoras theorem

H^2 = 20^2 + 21^2

H^2 = 841

H= 29

Sin theta = 20 / 29

Cos theta = 21/29

Atq

1-20/29+21/29 ÷ 1+ 20/29+21/29

After solving it

30/29÷70/29

30/29×29/70

= 3/7

Hope you get it