Question

The point (-1,4) is on the terminal side of angle theta in standard position. What are the values of sine, cosine, tangent of theta

Answer 1

cosФ = 0.97

sinФ = 0.292

tanФ = -4

Explanation:

A general point P(x,y) with an angle Ф has the following trigonometrical functions:

`sin\phi=(y)/(r)\\\\cos\phi=(x)/(r)\\\\tan\phi=(y)/(x)\\\\r=√((x)^2+(y)^2)`

For the point P(-1 , 4) you obtain:

`r=√((-1)^2+(4)^2)=√(17)\approx 4.123`

`sin\phi=(4)/(4.123)=0.97\\\\cos\phi=(-1)/(4.123)=0.242\\\\tan\phi=(4)/(-1)=-4`