Question

what is the exact value of cos (a)? your answer: not there yet, keep working

Explanation:

Step1: Recall cosine ratio definition

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

Step2: Identify adjacent and hypotenuse

For $\angle A$, adjacent side is $42$ and hypotenuse is $70$.

Step3: Calculate cosine value

$\cos(A)=\frac{42}{70}=\frac{3}{5}$

Answer:

$\frac{3}{5}$