Question

Use the unit circle to find the value of sin ³π/2 and cos ³π/2

Answer 1

1 and 0

Explanation:

sin(
`(\pi )/(2)` ) = 1, hence

sin³(
`(\pi )/(2)` ) = 1³ = 1

cos(
`(\pi )/(2)` ) = 0, hence

cos³ (
`(\pi )/(2)` ) = 0³ = 0

Answer 2

SIn³ π/2 = 1³ = 1

cos³ π/2 = 0³ = 0

Explanation:

Considering a circle of unit radius as shown in the image below.

So, OB = OA = 1 unit

Thus, by Pythagoras theorem,

OB² + OA² = AB²

So, AB² = 2

AB = √2 units

If ∠OAB = 90°

Then AB and OA approaches to OA. SO,

OB = AB = 1 unit and OA = 0

Thus,

SIn π/2 = P/H = 1/1 = 1

Cos π/2 = B/H = 0/1 = 0

So,

SIn³ π/2 = 1³ = 1

cos³ π/2 = 0³ = 0