Considering only the values of β for which sec β(1+cos β)(1−cos β) is defined, which of the following expressions is equivalent to sec β(1+cos β)(1−cos β)?

Question

select the correct answer below:

1

sec βtan β

cos β

sec β

sin βtan β

Answer 1

secB(1 + cosB)(1 - cosB)

= secB (1 - cos²B)

= secB (sin²B)

= 1/cosB (sin²B)

= sinB (sinB/cosB)

= sinBtanB