Question

For an angle θ with the point (15, −8) on its terminating side, what is the value of cosine?

Answer 1

Cos x = adyacent side / hypothenuse

adyacent side = x = 15

hypothenuse = √(x^2 + y^2) = √[(15)^2 + (-8)^2] = 17

cos x = 15/17 ≈ 0.88

Answer 2

Answer:

The value of cosθ is $\frac{15}{17}$

Step-by-step explanation:

It is given that  an angle θ with the point (15, −8) on its terminating side.

Here x=adjacent side=15 units and y=opposite side =-8 units,

Using pythagoras theorem,

$\text{hypotenuse}^2=\text{base}^2+\text{opposite side}^2$

$\text{hypotenuse}^2=(15)^2+(-8)^2$

$\text{hypotenuse}^2=225+64=289$

$\text{hypotenuse}^2=17$

Cosine is defined as

$\cos \theta=\frac{base}{hypotenuse}$

$\cos \theta=\frac{15}{17}$

Therefore the value of cosθ is $\frac{15}{17}$.