Exact Value of Trig Functions in Unit Circle

What is the exact coordinates of  3π/4 on the unit circle?

• (−√2∕2, √2∕2)

• (−√2∕2, −√2∕2)

• (−√3∕2, −√2∕2)

• (√2∕2, −√2∕2)

What is cos 90°?

• ½

• undefined

• 1

• 0

What is tan 90°?

• 1
• undefined
• 0
• ½

sin π/4

• √2∕2

• 1/2

• √3/2

• 0

sec 3π/2

• 0

• undefined

• 1

• -1

cos 5π/6

• -1/2

• 1/2

• √3/2

• -√3/2

tan 7π/4

• -1

• 1

• √2/2

• undefined

cos 4π/3

• -√3/2

• √3/2

• 1/2

• -1/2

cot 3π/4

• -√2/2

• -1

• 1

• √2/2

sin 7π/6

• 1/2

• -1/2

• √3/2

• -√3/2