Question

Given sin(−θ)= −1/4 and tanθ= 15√15 .

What is the value of cosθ ?

Answer 1

`\sin = (y)/(r) \\ \\ \tan = (y)/(x) \\ \\ \cos = (x)/(r) \\ \\ {x}^(2) + {y}^(2) = {r}^(2)`


`- \sin = ( - 1 \: = \: y)/(4 \: = \: r)`

`15 √(15) = (1)/(x) \\ \\ x = .017`

`\cos = (.017)/(4) = .0043`