Question

If theta=3pi/4

Sin theta=?
Cos theta=?

Answer 1

For ease of writing, θ
`=x`

`sin(x)=(1)/(√(2) )`

`cos(x)=-(1)/(√(2) )`

Explanation:

Our angle is
`x=(3\pi )/(4)`

To find our answers for
`sin((3\pi)/(4) )` and
`cos((3\pi)/(4) )`, we will need to use a unit circle. (I have attached the image of one).

Recall that the
`sin` of an angle is equal to the y-value of the corresponding ordered pair.

And the
`cos` of an angle is equal to the x-value of the corresponding ordered pair.

For the angle
`x=(3\pi )/(4)`, the ordered pair is
`(-(1)/(√(2)) }, (1)/(√(2) ) )`

This means that

`sin(x)=(1)/(√(2) )`

`cos(x)=-(1)/(√(2) )`