Question

question 10 of 10
what is cos 45°?
a. 1
b. $\frac{1}{sqrt{2}}$
c. $sqrt{2}$
d. $\frac{1}{2}$

Explanation:

Step1: Recall cosine definition

$\cos(\theta)=\frac{\text{adjacent}}{\text{hypotenuse}}$

Step2: Identify sides for 45°

Adjacent=1, Hypotenuse=$\sqrt{2}$

Step3: Calculate cos(45°)

$\cos(45^\circ)=\frac{1}{\sqrt{2}}$

Answer:

B. $\frac{1}{\sqrt{2}}$