Answer: [tex]cos\theta=-\dfrac{3}{5}[/tex]
Step-by-step explanation:
[tex]sin\theta = \dfrac{y}{r}=\dfrac{4}{5}[/tex]
Step 1: Use Pythagorean Theorem: x² + y² = r² to find the x-value
x² + 4² = 5²
x² + 16 = 25
x² = 9
x = 3
Step 2: Use the Quadrant to determine the sign of the x-value
Quadrant II Quadrant I
(--, +) (+, +)
Quadrant III Quadrant IV
(--, --) (+, --)
x is negative in Quadrant II
[tex]cos\theta=\dfrac{x}{r}=\large\boxed{-\dfrac{3}{5}}[/tex]
