Question

Assume that the circle is a unit circle. The sine of angle a is 0.7. Who’s is cos(a)?

Answer 1

`sin\text{ }a=0.7`
`\begin{gathered} sin\text{ a=0.7} \\ a=sin^(-1)0.7 \\ a=44.427^0 \end{gathered}`

on the second quadrant

`180-44.427=135.572`

Now cos a

`cos\text{ 135.572=-0.71414}`