Final answer:
To find the value of the cosine of angle M, use the cosine rule with the lengths of the sides of the triangle.
Step-by-step explanation:
To find the value of the cosine of angle M, we can use the cosine rule. The cosine rule states that in a triangle, the square of one side equals the sum of the squares of the other two sides minus twice the product of those two sides times the cosine of the angle between them.
In this case, we want to find the cosine of angle M, so we can use the lengths of the sides MO, NO, and MN.
Plugging in the values, we have:
MO^2 = NO^2 + MN^2 - 2(NO)(MN)cos(M)
8^2 = 15^2 + 17^2 - 2(15)(17)cos(M)
Simplifying this equation will give us the value of the cosine of angle M, which is approximately 0.67.