Sin, Cos, Tan Unit Circle

sin π/4 =

• 1/2

• √2 / 2

• √3 / 2

• 1

sin π/6 =

• 1/2

• √2 / 2

• √3 / 2

• 1

sin π/3 =

• 1/2

• √2 / 2

• √3 / 2

• 1

cos π/3 =

• 1/2

• √2 / 2

• √3 / 2

• 1

• 1
• 2
• 3
• 4

Based on the unit circle, what is the value of sin?

• y/r

• x/r

• r/y

• y/x

Answer explanation

The sin is always the y coordinate divided by the radius. With the unit circle that radius is 1.

sin 0

• 1

• -1

• 0

• Undefined

Using θ as a reference angle, mark the triangle sides as Opp, Adj, and Hyp. Label these on the triangle on your paper.

• Hyp

• x

• Opp

• OP

• Adj

• y

sinθ is positive in

• the 1st and 2nd quadrants

• the 1st and 3rd quadrants

• the 1st and 4th quadrants

• the 2nd and 3rd quadrants

• undefined

Answer explanation