Question

Please help me with my math! Thank You! :)

Answer 1

cosΘ =
`(4)/(5)`

Explanation:

Using the trigonometric identity

sin²x + cos²x = 1 ⇒ cosx = ±
`√(1-sin^2x)`

Given

sinΘ =
`(3)/(5)`, then

cosΘ = ±
`√(1-(3/5)^2)` = ±
`\sqrt{1-(9)/(25) }` = ±
`\sqrt{(16)/(25) }` = ±
`(4)/(5)`

Since Θ is in first quadrant then cosΘ > 0

cosΘ =
`(4)/(5)`

Answer 2

then Cos would be 4/5