In the standard form of quadratic

the discriminant is

In your quadratic, a = 1, b = -9 and c = -10
Now you need to plug these values into the expression for the discriminant.
Hello!
There are 4 cheetahs. There are 3 times as many elephants than cheetahs. Multiply:
4 • 3 = 12
12 + 4 = 16
Rebecca saw 16 animals at the zoo.
I really hope you found this helpful! :)
Answer:
(D) 
Step-by-step explanation:
Given: In triangle ABC, a=9, c=5 and ∠B=120°.
To find: The value of
.
solution: It is given that In triangle ABC, a=9, c=5 and ∠B=120°.
Now, using the law of cosines, we get

Substituting the given values, we get




which is the required value of
.
Therefore, option D is correct.