A point on the terminal side of an angle θ is given. Find the exact value of the indicated trigonometric function of θ.
-$( 4 , - 3 ) \quad$ Find $\cos \theta$.
A) $\frac { 4 } { 5 }$
B) $- \frac { 4 } { 5 }$
C) $\frac { 3 } { 5 }$
D) $- \frac { 3 } { 5 }$

Question

Quizplus · Accepted Answer

The cosine of an angle in a right triangle is the adjacent side over the hypotenuse. Here, the point (4, -3) suggests a right triangle with sides 4 (adjacent to θ) and -3 (opposite θ), with the hypotenuse found using the Pythagorean theorem: $\sqrt{4^2 + (-3)^2} = \sqrt{16 + 9} = \sqrt{25} = 5$. Thus, $\cos \theta = \frac{4}{5}$.

A Point on the Terminal Side of an Angle θ (4,−3)( 4 , - 3 ) \quad(4,−3)

A Point on the Terminal Side of an Angle θ $( 4 , - 3 ) \quad$