Question

Evaluate the following:

`(sin 20^@)/(cos 70^@)`

Answer 1

 Given that  `(sin 20^@)/(cos 70^@)`

Since `sin(90 - theta) = cos theta`

`=> (sin 20)/(cos 70) = (sin(90 - 70))/cos 70`

`=> sin 20/cos 70 = cos 70/cos 70`

`=> sin 20/ cos 70 = 1`

Therefore `(sin 20^@)/(cos 70^@) = 1`