Question

90 POINTS PLEASE HELP

Answer 1

sin/alpha = -0.8

Explanation:

Answer 2

`sin\alpha = - 0.8`

Explanation:

We have ,
`cos\alpha = (3)/(5)` , where
`\alpha` is located in IV quadrant! Let's find out value of
`sin\alpha` :

`sin\alpha = \sqrt{1-(cos\alpha )^2`

⇒
`sin\alpha = \sqrt{1-(cos\alpha )^2`

⇒
`sin\alpha = \sqrt{1-((3)/(5) )^2`

⇒
`sin\alpha = \sqrt{1-((9)/(25) )`

⇒
`sin\alpha = \sqrt{((25-9)/(25) )`

⇒
`sin\alpha = \sqrt{((16)/(25) )`

⇒
`sin\alpha = \pm {((4)/(5) )`

Value of
`sin\alpha` is dependent on which quadrant it is . Since, in question it's given that
`\alpha` is located in IV quadrant , So
`sin\alpha` is negative i.e.

⇒
`sin\alpha = - {((4)/(5) )`

⇒
`sin\alpha = - 0.8`

Therefore,
`sin\alpha = - 0.8` .