Δabc has three sides with these lengths: ab = 9, bc = 40, and ca = 41. what is the value of cos c?

Step-by-step explanation:

To find the we must use the cosine theorem.

The cosine theorem says that:

In this case:

So

i not know

step-by-step explanation:

rick has $1400 and sally has $1500

step-by-step explanation:

to find amount of money rick has after 10 years :

principal = $1000 , time = 10 years , rate = 4% annually

to find amount of money sally has after 10 years :

her friend gives to pay her $50 per year, therefore money she has after 10 years = 50 × 10 = $500

also, sally gets $1000 after 10 years,

therefore, total amount of money sally has after 10 years = 500 + 1000 = $1500

so, after 10 years : rick has $1400 and sally has $1500